EX1:
1. has never seen
2.remembered/forgot
3.sold
4.you had put/went
5.have not seen
6.has done
7.realized/ had forgotten
8.have never seen
9.arrived/has just gone
10.was/ has met
EX2:
1. when we arrived, he had gone home
+after he had gone home, we arrived
2. after having a snack, we had a look around the shop
3. the had no sooner begun work than the light failed
+No sooner had the light failed than they began work
+Hardly had they begun work when the light failed
4. we were happier than everyday before
5.before i had seen a real tiger for the first time, i went to the zoo
7.if the man had not been poor, he could have afforded accommodation
6.i would rather you had not gone to the party yesterday