句型转换（每空一词,句意不变）
1.The reason why he took Swiss nationality in 1901 is still a question.
____ he took Swiss nationality in 1901 ____ ____ ____.
2.Dreams are different from reality.
Dreams ____ ____ reality.
3.This is the best film I have seen.
I have ____ seen ____ ____film.
4.He burst into tears on hearing the news.
He ____ ____ ____ on hearing the news.