III
1. to pass
2. spending
3. being called
4. to use
5. to be met
6. to let
7. to be delivered
8. to be invented
IV.
1. It is pleasure to met him again
2. I find it interesting to study maths
3. I saw him leave the house early this morning
4. Jane was having a bath when Peter came to visit her
5. Jone has finished the reports before he went to bed
6. Bob should work harder for the exam
7. The boss made her type these letters before 5p.m yesterday
8. Before we went out, we has turn off all the lights