The little girl kept _____ the house, because she wanted to keep it _____.
The gravity on Mars is only about ________ of that on Earth.
It is hard to imagine what life __________ in 100 years.
My friend John insisted that he had seen ______ alien the day before.
--- What pleasant weather! Shall we go boating on the lake?--- _______.
--Excuse me, can you tell me _______? ---Sure. There’s a good restaurant on Renmin Road.