1 . 用篇章中划线词汇的适当形式补全以下句子。（有一个多余选项）

destroy     tough     target     original     threat     reduce

1. The police hid in the dark and waited for their ________ to come up.
2. The big fire ________ my house and made me lose all of my happiness.
3. Over-fishing is a big ________ to the sea animals and we must try our best to stop it.
4. Their ________ idea was to buy a new car, but now they decide to buy a second-hand one.
5. Students hope that teachers ________ their homework so that they’ll have more time to relax.