如果要求用户输入年龄必须大于20小于30，则以下描述正确的是（）。

A.在输入掩码处输入>20AND<30

B.在默认值处输入>20AND<30

C.在有效性规则处输入>20AND<30

D.在有效性问本处输入>20AND<30

--- Hi, Terry, can I use your computer for a while this afternoon?

--- Sorry. ______.

A．It' s repaired

B．It has been repaired

C．It's being repaired

D．It had been repaired