Наверное не по 3 предложения, а по 4
negative:
She did not eat potatoes because she was not hungry.
They didn't go camping with the class.
He didn't come back for dinner.
We didn't work on the problem from the text.
positive:
He worked in this big factory.
She studied at the top university in the country
.
They knew how to solve these problems.
They took a train to a nearby town.
question form:
Did they take a train to a nearby town?/ Yes, they did.
Did they go camping with the class?/ No, they didn't.
Did she study at the top university in the country?/ Yes, she did.
Did they know how to solve these problems?/ No, they didn't know.
Объяснение:
1.them
2.her
3.it
4.him
5.it
6.her
7.it
8.them
9.him
10.us