The guard keeps watch at the gate.—So he does. Only those knows well could be let in.

Nowadays,people have to ________ natural disasters caused by global warming. [ ]

Shall I tell John about it? —— No, you＿＿＿＿. I don’t know his telephone number.

new boss offers me a much highersalary, ______ I can get a considerable bonus at the end of the year

He is very tired，so he needs some time __________ duty for relaxation and rest．