当你向别人介绍你的朋友Jim时，你应说：＂______________＂。

_____ great fun it is! And _____ good time we are having!

Why is Tom absent?—He must be sick，__________?

Nowadays, Chinese acupuncture has become popular round the world, __________ have other traditional Chinese medicines.

I’m fond of my sister, but she has a serious shortcoming. She _______ be really stubborn.