Chọn từ thích hợp điền vào chỗ trống:

Keep quiet. You _______ talk so loudly in here. Everybody is working.

He is unreliable. What he says _______ be believed.

She ___ be ill. I have just seen her playing basket ball in the school yard.

Marcela didn’t come to class yesterday. She______ an accident.

Susan ___ hear the speaker because the crowd was cheering so loudly.

Hiking the trail to the peak _______ be dangerous if you are not well prepared for dramatic weather changes. You _______ research the route a little more before you attempt the ascent.

_______ I have a day off tomorrow? - Of course not. We have a lot of things to do.