NC L86 What have you done?

现在完成时：

have/has + 动词过去分词

She has already aired the room.

She has not aired the room.

Has she already aired the room?

Yes,she has.  No,she hasn’t.

What has she done?

do/does/doing/did/done

go/goes/going/went/gone

动词原形变过去分词规则：

1. +ed

2. 以不发音的e结尾，+d

3. 辅音+y结尾，变y为i，+ed

4. 重读闭音节（辅元辅），双写最后一个字母，+ed

5. 特殊情况