1 . 为了回应这一问题，各界学者提出了很多对策和措施。
In order to ____________ ____________ this problem, various academics proposed many measures and steps.

2 . 我们决不允许香港和大陆脱离关系。
In no case will we allow Hongkong to ________ ________ ________ the mainland of our motherland. (根据汉语提示完成句子)

3 . It must be great fun_________ to the moon in a spaceship.

A．flying

B．flies

C．to have flied

D．to fly

4 . 我有点焦虑，因为我想给别人留下一个好的印象。
I was a little anxious because I wanted to ________ ________ ________ ________ on others.