9.
2. They have been playing together for hours.
3. He had been waiting for the bus for half an hour.
4. He had been working in the barn.
5. She had been sitting in the sun for hours.
6. They had been discussing business problems for four hours.
10.
1.
2) stood
3) escaped
2.
1) did
2) planned
3) waited
11.
A.
2) took
3) sat
4) left
5) didn't catch
B.
1) was
2) forgot
3) got
4) was
C.
1) had
2) got up
3) finished
4) had
D.
1) went
2) had
3) got
4) realized
5) forgot
6) went
12.
2) had
3) ate
4) only drove
5) left
6) locked
7) tried
8) called