Read the passage. 1) sosi left her backpack on the stool, and it disappeared. 2) ana thought she saw the backpack near a worktable in the science lab. 3) she was right. 4) the teacher had moved the backpack so that a student could use the stool. 5) sosi was glad to have her backpack back and ana for finding it.
which sentence contains an error in pronoun-antecedent agreement? sentence 1 sentence 2 sentence 4 sentence 5

The answer is 4. This sentence contains an error in pronoun-antecedent agreement when repeating the word backpack, whre it should be used the object pronoun it.  Since the word backpack was already mentioned in 1) "her backpack"; in 2) "the backpack", it is not necessary to repeat it. One of the important uses of pronouns is in helping to avoid repetitions.

1) Sosi left her backpack on the stool, and it disappeared.

Explanation:

the eye wink at the hand; yet let that be / which the eye fears, when it is done, to see.