12.
2 What were you doing at eight o'clock last night?
3 Helen wasn't working yesterday morning. She was at the doctor 's.
4 At four o'clock yesterday afternoon we were playing in the garden.
5 Why were they wearing the best clothes ?
6 Dave wasn't using when is broken down.
13.
3 have done
4 have climbed
5 have explored
6 have seen
7 has taken
8 we haven't been