1 . _______ was responsible for this crime is a dangerous man. (用适当的词填空)

2 . It’s uncertain ________is unavoidable in the author’s rescue work. (用适当的词填空)

3 . It’s unbelievable ________ they should deny my request. (用适当的词填空)

4 . It remains to be seen ________the situation has happened. (用适当的词填空)

5 . ________ you didn’t go to the talk was a pity. (用适当的词填空)

6 . It was thought ________by 1998 there were only six to nine wild Siberian tigers living in the remote region.(用适当的词填空)

7 . ________she says will not make any difference to our arrangements.（用适当的词填空）

8 . It is a fact _________________ English is a tool in modern society. (用适当的词填空)

9 . We usually think _________________ we can’t get seems better than what we have. (用适当的词填空)

10 . _________________ he solved the challenging problem successfully interested all of us. (用适当的词填空)