Frank often wears a mask ________he can keep fit in the foggy and hazy (霾) weather.
_____does your sister do? She is a nurse.
The noisy boy ______stand up by a teacher.
Are you worried about the coming exam? No, I think the more_____ you are, _____mistakes you’ll make.
I didn’t sleep ______last night. I feel tired now.
When shopping, keep your eyes ______for those energy-saving machines.