—Why didn’t you try your best to get on the bus?—I tried to , but _______ I could, it started moving.
The waterfall can be seen _______. Its sound may be heard _______ two miles. It looks even more beautiful _______, I think.
He looked around nervously to ________ that there was nobody following him.
It saves time in the kitchen to have things you use a lot _______ easy reach.
Effective measures should ________ and laws should _______ to protect pandas. Otherwise, they are certain to die out.
The tree over there is so tall that I suppose it _______ nearly twenty metres.