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 ________.