Like some of my classmates，I cannot live up to my teachers' expectations；________，I let them down.

 It was because it had been raining for several days, leading to a flood over the fields and the villages that many people fell _______ without foods and shelters.

____ the morning of my mother’s birthday, I usually help my mother do some housework.

I’d like to do something for you_____ everything you have done for me.

—Why do you suggest we buy a new machine?—Because the old one has been damaged ______.