At the top of the high mountains, there is very _____ oxygen in the air.

How would you like if you were watching your favorite TV program and someone came into the room and just shut it off without asking you

Is it interesting to play computer games—Yes, _____ you are interested in playing computer games, you’llhave trouble giving it up.

With no onethem，thetwo thieves stole into the house

I _____ sooner but I didn’t know that theywere waiting for me．