Dear me! What a beautiful computer!—My grandma bought ___for my sister and me. It’s ours.
Why do English people talk so often about the weather when they start a talk? — Because the weather is a(n) ________ topic (话题).
Scientists say it may be five or six years _____ it is possible to test this medicine to human patients.
There are many volunteers _________ are helping the children in Sichuan.
My sister is only four years old, but she can look after ________ now.