--- Is Mary _______ friend, Alice?---No, she is a friend of ______.
This machine is very easy to use.______ can learn to use it in a very short time.
The game is _____ funny that many of them like it.
I'm very glad _____ you.
More and more people in the world enjoy _____ now.
当经介绍后认识某人,你应该说: