В выражениях "он сказал (знал, был...),что ... во второй части предложения "настоящее" переходит в "прошлое", а "прошлое" в " паст перфект"
1 was staying
2 had lost
3 studied
4 should finish
5 worked
6 ha worked
7 was
8 was plaeing
9 would come
10 had posted
7
5