---who______it be that is knocking at the door? ---It_______be Father, but I’m not sure.
Children to whom parents always ___________ soon become selfish.
Last week only two men came to look at the house, ________ wanted to buy it.
It was for this reason ________ her parents moved out of London and settled down in a mountain village.
Her car has been very dirty. She has got to _______.
What she spends a month at university___________ no more than 500 yuan.