根据句意和首字母的提示，写出单词。

1. They are doing some r _______ into the effects of brain damage.

2. We will have to clear some s ______ to make room for the new sofa.

3. The report describes things as they r _______ are. .

4. Many social servers are still provided by v _______ societies.

5. Look! He's got a hearing aid—he's d ________.