用所给词的适当形式填空。
There used to be many           (wolf)， but only a few of them remain today.
At present， Chinese is           (wide) used around the world.
The doctor advised my father           (not smoke) any more.
We should be           (friend) to others at any time.
It’s reported that Chinese couples can have their           (two) child if one of them is an only child.