Happiness is a butterfly, which, when pursued, is always just beyond your grasp, but ________, if you will sit down quietly, may alight upon you.
19.This library was ranked ______ one of the best libraries in the world_____ honor of its contribution to the people.
18.---Can I borrow your car this Sunday? ---______________.I won’t use it anyhow.
17.Puppy love is _________.
16.He looked around and caught a man _______ his hand into the passenger's pocket.
15.– How cold it is! I wonder how grass survive under such heavy snow. --Don’t worry.There is a lot of air in loose snow which _______.