Between 4.5 and 3.8 billion years ago, the earth became so ______ that it was not clear whether the shape would last or not.
I asked him how much ________________.
As we all know,parents are concerned ________their children’s study,because it is concerned ________their future.
—I have two suggestions: one is to go to the cinema, the other is to have a drink. —Well, personally I prefer the _____one. I don’t like films very much.
There’ s a big difference between saying you’ll do something and ________doing it.
She understood what I was talking about,________it was the first time we had spoken together.