Everyone appeared to be having a good time. my impressions may have been wrong.
a. in fact
b. in other words
c. furthermore
d. of course

The answer is letter A.

In fact are the words that correctly fit the sentence. It gives meaning to the person's wrong assumptions about the event that had occurred. The other three choices are not appropriate for this sentence because their purpose in a sentence is to explain something in further detail. 

1) The sentence in which I find a verb phrase is b. I believed every word he said. When you are asked to find a verb phrase the first thing you should do is to define the predicate of the sentence. The predicate always contains needed verb phrase as you can see it in the option B. It also can be founded in the clause of the sentence but it this case it is placed right in the predicate ‘believed’ is a verb phrase. 2) The topic which would lend itself only to a formal style of writing is D. psychological effects of nuclear weapons. When deciding which style of writing you should employ, pay attention to the main theme of writing. According to the name of the topic the text must contain objective writing style that also should include citations. 3) The statement which would be considered inappropriate in formal writing is a. he hates to be late as this sentence contains word order that does not suits the formal style of writing. Task requires you to understand the difference between formal and informal writing and this option is the most suitable as it contains using sort of colloquial words/expressions that must be avoided. 4) For the greeting in a business letter when you don't know the name of the person who will be reading it, the following which is least likely to conform to present-day usage is A. dear editor. If you are not informed about the name of the person you are writing to, the only polite and proper greeting is Dear Sir/ Madam. Nowadays you will never come across ‘Dear Editor’ in formal business letter. 5) The sentence which contains an unnecessary word is c. the snake raised up its head and struck. There is one unnecessary word used in the sentence which does not make much sense. The word ‘up’ should be withdrawn because the sentence asks the exact same question with or without the word up, so it both not necessary and makes no difference in usage at all. 6) The run-on sentence is a. i thought about what he'd said soon i realized he was right. The task is to follow main characteristic of the run-on sentence which contains two independent clauses that are not linked with a conjunction so that it could be two complete sentence. You can make it up like this : I Thought about what he'd said. Soon i realized he was right. 7) The connective that belongs in the blank in the following sentence is ‘however’. Ilike to play baseball.However, i can't throw a ball very well. This task requires knowledge of using the conjunctive adverbs correctly. As you can see, the second sentence expresses opposed meaning to the previous one, so you should put contrastive conjunctive adverb to complete it. 8) The sentence which has a compound predicate is d. she washed the shells and dried them in the sun. This task is aimed to pays your attention to the complex sentence that has a predicate which consists of many verbs that belong to one object. They are usually joined by such words as ‘and’, ‘or’ and so on. As you can see, the subject is ‘she’ and she performs several actions. 9)The following which is correct in regard to the use of formal english is definitely a. in formal business correspondence, it's best keep the language impersonal. You have to follow the main requirements of writing a formal letter and the main rule is to make your writing neutral and concise, without personal appealing to a reader and using conjunctions etc. 10) The following best illustrates a pair of sentences that are joined by an understood relationship is b. detective smiley scanned the dim hallway. he pulled his pistol from its holster. As you can see, there is recognizable logical sequence of these two sentence that are linked with each other sensibly. When reading them you can imagine a piece of a short story whereas the other option contain completely unrelated sentences. 12) This one “c. a good connection between two paragraphs is an implied transition.” is the best statement which is correct about connecting paragraphs. Implied transition makes a logical connection between paragraphs by using transitional words or phrases. 13) This one “d. when we stopped by the garden.” is the group of words is a sentence fragmen. Sentence fragment is a group of words which is not a complete sentence. That option is a fragment as the sentence don’t have logical start and ending. 14) Here we need to choose the connective that belongs in the blank in the following sentence. So the sentence should look like this: c. Of course, my impressions may have been wrong. This option is the only one which makes the most sense. But anyway it depends on a situation.

1) The sentence in which I find a verb phrase is b. I believed every word he said. When you are asked to find a verb phrase the first thing you should do is to define the predicate of the sentence. The predicate always contains needed verb phrase as you can see it in the option B. It also can be founded in the clause of the sentence but it this case it is placed right in the predicate ‘believed’ is a verb phrase. 2) The topic which would lend itself only to a formal style of writing is D. psychological effects of nuclear weapons. When deciding which style of writing you should employ, pay attention to the main theme of writing. According to the name of the topic the text must contain objective writing style that also should include citations. 3) The statement which would be considered inappropriate in formal writing is a. he hates to be late as this sentence contains word order that does not suits the formal style of writing. Task requires you to understand the difference between formal and informal writing and this option is the most suitable as it contains using sort of colloquial words/expressions that must be avoided. 4) For the greeting in a business letter when you don't know the name of the person who will be reading it, the following which is least likely to conform to present-day usage is A. dear editor. If you are not informed about the name of the person you are writing to, the only polite and proper greeting is Dear Sir/ Madam. Nowadays you will never come across ‘Dear Editor’ in formal business letter. 5) The sentence which contains an unnecessary word is c. the snake raised up its head and struck. There is one unnecessary word used in the sentence which does not make much sense. The word ‘up’ should be withdrawn because the sentence asks the exact same question with or without the word up, so it both not necessary and makes no difference in usage at all. 6) The run-on sentence is a. i thought about what he'd said soon i realized he was right. The task is to follow main characteristic of the run-on sentence which contains two independent clauses that are not linked with a conjunction so that it could be two complete sentence. You can make it up like this : I Thought about what he'd said. Soon i realized he was right. 7) The connective that belongs in the blank in the following sentence is ‘however’. Ilike to play baseball.However, i can't throw a ball very well. This task requires knowledge of using the conjunctive adverbs correctly. As you can see, the second sentence expresses opposed meaning to the previous one, so you should put contrastive conjunctive adverb to complete it. 8) The sentence which has a compound predicate is d. she washed the shells and dried them in the sun. This task is aimed to pays your attention to the complex sentence that has a predicate which consists of many verbs that belong to one object. They are usually joined by such words as ‘and’, ‘or’ and so on. As you can see, the subject is ‘she’ and she performs several actions. 9)The following which is correct in regard to the use of formal english is definitely a. in formal business correspondence, it's best keep the language impersonal. You have to follow the main requirements of writing a formal letter and the main rule is to make your writing neutral and concise, without personal appealing to a reader and using conjunctions etc. 10) The following best illustrates a pair of sentences that are joined by an understood relationship is b. detective smiley scanned the dim hallway. he pulled his pistol from its holster. As you can see, there is recognizable logical sequence of these two sentence that are linked with each other sensibly. When reading them you can imagine a piece of a short story whereas the other option contain completely unrelated sentences. 12) This one “c. a good connection between two paragraphs is an implied transition.” is the best statement which is correct about connecting paragraphs. Implied transition makes a logical connection between paragraphs by using transitional words or phrases. 13) This one “d. when we stopped by the garden.” is the group of words is a sentence fragmen. Sentence fragment is a group of words which is not a complete sentence. That option is a fragment as the sentence don’t have logical start and ending. 14) Here we need to choose the connective that belongs in the blank in the following sentence. So the sentence should look like this: c. Of course, my impressions may have been wrong. This option is the only one which makes the most sense. But anyway it depends on a situation.

Question 3) The best sentence here that illustrates an understood relationship is most likely D - 'Detective Smiley scanned the dim hallway. He pulled his pistol from its holster'. This is because the reader is already likely to understand the assigned role of a detective in the story, and that a dim hallway might therefore indicate danger that necessitates him to be armed.

Question 10) The connective that belongs in the blank in this sentence would be answer A. 'Everyone appeared to be having a good time. Of course, my impressions may have been wrong.' This is due to the fact that 'Of course' is the only available connective that implies a negation of the previous sentence.

Question 13) The correct answer here is B. 'In formal business correspondence, it's best to keep the language impersonal'. This is true, as personal language and familiarity is usually considered unprofessional in a business setting.

Question 15) The correct answer is A - the sentence that has a dangling modifier is 'On the way to the bank, the interest rates went down', as in this sentence it could be argued that it is written as if the interest rates themselves are on the way to the bank.

Question 16) The correct answer is B - the statement that is correct about connecting paragraphs is 'You can use a pointing word that refers to a word in the previous paragraph.'

Question 3) The best sentence here that illustrates an understood relationship is most likely D - 'Detective Smiley scanned the dim hallway. He pulled his pistol from its holster'. This is because the reader is already likely to understand the assigned role of a detective in the story, and that a dim hallway might therefore indicate danger that necessitates him to be armed.

Question 10) The connective that belongs in the blank in this sentence would be answer A. 'Everyone appeared to be having a good time. Of course, my impressions may have been wrong.' This is due to the fact that 'Of course' is the only available connective that implies a negation of the previous sentence.

Question 13) The correct answer here is B. 'In formal business correspondence, it's best to keep the language impersonal'. This is true, as personal language and familiarity is usually considered unprofessional in a business setting.

Question 15) The correct answer is A - the sentence that has a dangling modifier is 'On the way to the bank, the interest rates went down', as in this sentence it could be argued that it is written as if the interest rates themselves are on the way to the bank.

Question 16) The correct answer is B - the statement that is correct about connecting paragraphs is 'You can use a pointing word that refers to a word in the previous paragraph.'

1) B. Psychological Effects of Nuclear Weapons
2) B. Looking up from his computer monitor, —— mopped his brow, exhaled sharply, and picked up his phone.
3) C. Sally lives with her parents, although she could afford her own apartment.
4) D. I went home and ate and ate.
5) D. Dangling modifier 
6) A. On the way to the bank, the interest rates went down. 
7) A. As Jake was reading the letter from June yet again, the flight attendant coughed gently to get his attention. 
8) C. Why don't you leave before the crowd arrives?
9) A. Of course 
10) A. Running all the way, he got there early.

Question 3) The best sentence here that illustrates an understood relationship is most likely D - 'Detective Smiley scanned the dim hallway. He pulled his pistol from its holster'. This is because the reader is already likely to understand the assigned role of a detective in the story, and that a dim hallway might therefore indicate danger that necessitates him to be armed.

Question 10) The connective that belongs in the blank in this sentence would be answer A. 'Everyone appeared to be having a good time. Of course, my impressions may have been wrong.' This is due to the fact that 'Of course' is the only available connective that implies a negation of the previous sentence.

Question 13) The correct answer here is B. 'In formal business correspondence, it's best to keep the language impersonal'. This is true, as personal language and familiarity is usually considered unprofessional in a business setting.

Question 15) The correct answer is A - the sentence that has a dangling modifier is 'On the way to the bank, the interest rates went down', as in this sentence it could be argued that it is written as if the interest rates themselves are on the way to the bank.

Question 16) The correct answer is B - the statement that is correct about connecting paragraphs is 'You can use a pointing word that refers to a word in the previous paragraph.'

1) B. Psychological Effects of Nuclear Weapons
2) B. Looking up from his computer monitor, —— mopped his brow, exhaled sharply, and picked up his phone.
3) C. Sally lives with her parents, although she could afford her own apartment.
4) D. I went home and ate and ate.
5) D. Dangling modifier 
6) A. On the way to the bank, the interest rates went down. 
7) A. As Jake was reading the letter from June yet again, the flight attendant coughed gently to get his attention. 
8) C. Why don't you leave before the crowd arrives?
9) A. Of course 
10) A. Running all the way, he got there early.