can anyone help me with providing an explanation for each of the correct answers

Subject-verb agreement A
1a. Did you know a famous animal-rights activist has criticized horseracing because of the dangers involved? 1b. Did you know a famous animal-rights activist have criticized horseracing because of the dangers involved
Subject-verb agreement B
2a. Peer editing academic papers require critical-thinking skills and diplomacy.
2b. Peer editing academic papers requires critical-thinking skills and diplomacy.
Subject-verb agreement A
3a. Vitamins that are sold in a health-food store are not regulated by the Food and Drug Administration.
3b. Vitamins that are sold in a health-food store is not regulated by the Food and Drug Administration.
Using regular and irregular verbs A
4a. John has become a rather good actor.
4b. John has became a rather good actor.
Using regular and irregular verbs A
5a. Some athletes have taken drug tests to prove they are not on steroids.
5b. Some athletes have took drug tests to prove they are not on steroids.
Using regular and irregular verbs B
6a. I lay my book on the table, but now I cannot find it.
6b. I laid my book on the table, but now I cannot find it.
Using the correct form of be and have in the present tense B
7a. I was interested in working on the presidential campaign if the opportunity still exists.
7b. I am interested in working on the presidential campaign if the opportunity still exists.
Verb form and verb tense B
8a. Since American Idol premiered on television, many talented contestants have appeared on the show.
8b. Since American Idol premiered on television, many talented contestants appeared on the show.
Verb form and verb tense A
9a. The ancient Egyptians built pyramids as burial sites for their leaders.
9b. The ancient Egyptians have built pyramids as burial sites for their leaders.
Identifying antecedents A
10a. The antecedent in the following sentence is students: Students in online classes have to be organized to keep up with their assignments.
10b. The antecedent in the following sentence is class: Students in online classes have to be organized to keep up with their assignments.
Identifying antecedents B

These explanations should get you started.

1. The subject (activist) is singular and needs a singular verb (has criticized).

4. The helping verb "has" needs the past participle "become."

10. The students (plural) is the antecedent of the pronoun (their).

Certainly! Here are explanations for each of the correct answers:

1a. The correct answer is 1a. "Did you know a famous animal-rights activist has criticized horseracing because of the dangers involved?" In this sentence, the subject ("a famous animal-rights activist") is singular, so the verb should also be in singular form ("has criticized").

2b. The correct answer is 2b. "Peer editing academic papers requires critical-thinking skills and diplomacy." In this sentence, the subject ("peer editing academic papers") is singular, so the verb should also be in singular form ("requires").

3a. The correct answer is 3a. "Vitamins that are sold in a health-food store are not regulated by the Food and Drug Administration." In this sentence, the subject ("vitamins that are sold in a health-food store") is plural, so the verb should also be in plural form ("are not regulated").

4a. The correct answer is 4a. "John has become a rather good actor." In this sentence, the verb "become" is an irregular verb, and the correct form in the present perfect tense is "has become."

5a. The correct answer is 5a. "Some athletes have taken drug tests to prove they are not on steroids." In this sentence, the verb "take" is a regular verb, and the correct form in the present perfect tense is "have taken."

6b. The correct answer is 6b. "I laid my book on the table, but now I cannot find it." In this sentence, the verb "lay" is the past tense of "lie," and the correct form in the past tense is "laid."

7b. The correct answer is 7b. "I am interested in working on the presidential campaign if the opportunity still exists." In this sentence, the present tense form of the verb "be" ("am") is used to match the subject ("I").

8a. The correct answer is 8a. "Since American Idol premiered on television, many talented contestants have appeared on the show." In this sentence, the present perfect tense form of the verb "appear" ("have appeared") is used to indicate actions that started in the past and continue into the present.

9a. The correct answer is 9a. "The ancient Egyptians built pyramids as burial sites for their leaders." In this sentence, the verb "build" is a regular verb, and the correct form in the past tense is "built."

10a. The correct answer is 10a. "The antecedent in the following sentence is students: Students in online classes have to be organized to keep up with their assignments." In this sentence, the noun "students" is the antecedent of the pronoun "their." It refers to the students themselves.