20. I have done (現在完成時) 與 I did (一般過去時) 比較 – Grammar in use Course Content 20. I have done (現在完成時) 與 I did (一般過去時) 比較 Grammar in Use Unit 20.1 Grammar in Use Unit 20.2 Grammar in Use Unit 20.3 Grammar in Use Unit 20.4
