补全对话，填入所缺词汇。
Alan : Hello, Bill. 1 do you often come to school?
Bill: I often come 2 a bus. What 3 you?
Alan: Oh, I usually come _ 4 bike, but sometimes. I come 5 foot.
Bill: 6 7 is it from your home to school?
Alan: It's two kilometres.
Bill: 8 9 does it take?
Alan: It 10 me about 10 minutes on my bike and 20 minutes to walk.
