Complete the sentences with the correct form of the verbs in brackets.

They…………..(finish) their dinner.

He …………………(not start) doing his homework.

……………….you …………………(swim) in a lake?

I ……………………………………….(not climb) a really high mountain before.

………………..he ever …………………..(be) to this part of the country before?

We ………………….(learn) a lot about history on this holiday.

My sister …………………….(not watch) TV for nearly two weeks.