Answer:
9. A. are
10. B. is
11. Mariel drank her milk before going to bed.
12. Leah and Angelica swim every morning.
13. My cat runs very fast.
14. We go to the farm every vacation.
15. Marlon ate his breakfast early during school days.
Explanation:
The helping verbs used in a sentence depends on the number of nouns or pronouns and the tense of the sentence. This means that plural nouns will have plural helping verbs and so on.
9. Marla and Marlene are twins. They like to wear similar shirts. Here, the nouns are "Marla and Marlene" thus plural. And so, the verb will be "are".
10. January is the first month of the year. here, we use "is" because the noun "January" is singular and also it is a universal truth.
The use of the correct forms of verbs depends on the nouns as well as the structure of the sentence.
11. Mariel drank her milk before going to bed. Here, we use "drank" as the sentence is talking about a past event.
12. Leah and Angelica swim every morning. Here, the verb remains the same as the time is "every" morning and there is no change in it for the tense.
13. My cat runs very fast. Here, the cat is singular as well as the sentence is talking about a current action.
14. We go to the farm every vacation. Here, the time is 'every"', thus the verb will continue to be in the present tense. Also, since the noun is plural, thus the use of the verb "go" instead of "goes".
15. Marlon ate his breakfast early during school days. Here, we use the past tense of the verb "eat" as the action is about a past event.
