Ⅰ.单句语法填空
1．What caused the serious traffic accident __remains__ (remain) unknown.
2．It is a pity __that__ we won’t be able to go camping this Sunday.
3．Whoever __pollutes__(pollute) the environment will be punished.
4．__That__ we shall be late is certain.
5．It is not sure __whether__ he will come to your house or not.
6．(2019·全国卷Ⅰ) The deadlines and __what__ you need to apply depend on the program.
7．__What__ you need is a great teacher who lets you make mistakes.
8．It’s possible __that__ we all have compromised conversational intelligence.
9．__It__ is a fact that the earth is round.
10．__What__ parents say and do has a lifelong effect on their children.
