---It’s cloudy outside. Please take an umbrella. --- ______.
The clever boy made a hole in the wall, _______ he could see _____ was going on inside house.
------How do you like the book?-----It’s quite different from ___ I read last month.
Can you lend me the novel ______ the other day?
I have seen trees, _____ open at sunrise and close at sunset.
___ is known to all, China is a developing country, belonging to the third world.