—Recent pressure at work may ______ his behavior.
—Can you keep an eye on my bag? I need to go to the washing closet.— __________. It'll be safe with me.
—What a noise! I can hardly stand it.—It __________ as if they are having a party next door.
—But I don't know how to play the piano.— __________.
He tried his best to solve the problem, __________ difficult it was.
__________ private cars are bringing us convenience, they may also cause more traffic accidents and pollution.