1 . 各国不仅找到了一条通向未来的道路，这条路不踩在过去的遗迹上，而且还了解到各国可以共同努力建设更美好的明天。
_________ _________ had the countries found a path to the future that did not run over the relics of the past, _________ they had _________ learnt that it was possible for countries to work together to build a better tomorrow.

2 . 我不外向，因此现在有点焦虑。
I’m not __________________________ right now.

3 . 你永远不会看到我没有书或笔。
You will __________see me __________a book __________a pen.

4 . I was having breakfast with my three children ________ water started filling.

A．when

B．then

C．while

D．as

5 . Some people get in touch with each other by mobile phones__________ others keep contact with each other by e-mail.

A．when

B．before

C．while

D．since