1 . 观察下列句子，判断划线部分属于哪种名词性从句(主语从句、宾语从句、同位语从句、表语从句)，并在题目后的答题线上写出答案。
1. It is known to all that the Earth turns around the Sun.
2. He will talk to us about what he saw in the United States.
3. The question I want to ask you right now is whether we should ask the police for help.
4. When and where the meeting will be held hasn’t been decided yet.
5. I find it necessary that we should try every means to practise our spoken English every day.
6. The news that China had successfully launched   Shenzhou VI into space made all of us excited.
7. The promise she made yesterday was that she would finish all her homework within two days.
8. What I want to do right now is to sit down and do nothing at all.
9. The possibility that_pleasant_smells_might_reduce_pain has recently been suggested by new research.
10. Scientists used to believe that mothers_recognize_their_children_by_sight_only.