— Did you telephone Mr. Brown?— Yes, he ____ back before tomorrow morning.[ ]

Please don’t step on the grassland. Can’t you see the sign “______ the grassland” —Sorry, sir! I didn’t see it.

_________, some famous scientists have the questions of being both careful and careless.

Must I turn off the gas after cooking?—Of courseYou can never be ________ careful with that

I wonder when the group of teenaged girls at the gate of the hotel .— Not until Coco Lee . They are all her fans.