根据句意和汉语注释，写出单词的正确形式。

1. We went to an           (展览) of Chinese paintings at the museum yesterday.

2. TV sets are          (可获得的) in any shopping mall.

3. Many animals            (消失) long ago because of hunting.

4. If you see the suspect, you must call the police            (立即).

5. The             (工程师) are designing a new bridge.