I think it is B or C because you have to add ed to the word (finish) and (gather) to make it sound right and make sense.

Ms.Sue can you help me I'm stuck on this question.

17. Based on the words in parentheses, which one of the following sentences needs a past participle?

A. (Look) out for snakes, we moved through the swamp.
B. They just (finish) breakfast when the phone rang.
C. Last night, parents (gather) at the elementary school.
D. We have (eat) late every night.

It's B. It should be they had just finished breakfast when the phone rang.

20. Which of the following statements is true regarding sentence components?


A. Often the subject will act upon the object.
B. Every sentence must have an object.
C. The predicate can be a noun or a verb.
D. The object can be a noun or a verb.

I think it is A.Often the subject will act upon the object.

Yes, it's A.

Thank you so much Ms.Sue for helping me,I really appreciate it.That was all of the questions that I had for today :)

You're very welcome, Sarah.

Ms.Sue I just submitted my answers and these two were wrong.

17. Based on the words in parentheses, which one of the following sentences needs a past participle?


A. (Look) out for snakes, we moved through the swamp.
B. They just (finish) breakfast when the phone rang.
C. Last night, parents (gather) at the elementary school.
D. We have (eat) late every night.

18. Which one of the following sentences contains an object pronoun?


A. It's a good day for fishing.
B. You saw what you expected to see.
C. I think that cat is mine.
D. Jim accused her of stealing the picture.