Supply the correct form of the verbs in brackets.

1. Sharks (hunt) for hundreds of years.

2. Nowadays human beings mainly (kill) sharks for sport, but until quite recently great numbers of sharks (kill) for their oil. Shark oil (use), to light lamps, and shark liver oil (find) to be rich in vitamins A and D. Sharskin also (have) its uses. Its rough surface (make) it suitable for use on sword handles, and it (use) for many years as a makers of fine furniture as well as in the manufacture of small articles such as shoes and purses. Sharks' teeth (still wear) as decorataions, of course, by Pacific islanders, but when the teeth (fix) in war clubs, they (have) a rather different effect.

3. During the flight, water (add) to the dried food to make it more or less like normal food, hot water (produce) hot food.

4. For the longer Skylab flight, a new kind of food has been developed. It (pack) in a aluminium cans, which (open) by pulling a ring on top. The cans (heat) on special metal trays, and the food can then (eat) with a knife and fork.

5. Mr. Reed (be) an engineer for over 25 years. After (leave) Manchester University, in 1966, he (spend) a year in the USA, and then (work) in Indonesia for three years. The following year, 1970-1971, he (do) a management training course in London. After this, he (decide) (go) abroad again, first to Turkey, where he (help) plan the bridge across the Bosphorus, and then to Saudi Arabia, where he (supervise) the building of a large hospital. In 1976 he (return) to Britain and (take) up a post in the oil city of Aberdeen, Scotland. He (live) in Britain since then.

6. He ought to have gone along a side streel. That's what he should (do).