I. 根据下列各句句意及所给单词的首字母或汉语提示，写出该单词的正确形式。
1. There were some photos of ________(野生动植物)in the document.
2. He still _________ (保留)his opinion on some points.
3. They are pulling their troops out of the battle z________.
II. 用所给单词的适当形式填空。
1. She put on dark glasses as a ______ (protect) against the strong light.
2. Many parents feel a sense of ________ (lose) when their children leave home.
3. Winter is te best time for ________(hunt) in mountain areas.
4. There has been a steady _________(decrease) in population in this city.
