互动封闭仿真课堂1、智能交互 2、电子板书式视频教学 3、5分钟一次互动问答 4、封闭课堂
1. The first use of atomic weapons was in 1945, and their power _______increased enormously ever since. (2004 上海，29)
A. is B. was C. has been D. had been
2. —You were out when I dropped in at your house.
—Oh, I ______for a friend from England at the airport. (2004 福建，21)
A. was waiting B. had waited
C. am waiting D. have waited
3. —The window is dirty. (2004 广西，25)
—I know. It _______for weeks.
A. hasn’t cleaned B. didn’t clean
C. wasn’t cleaned D. hasn’t been cleaned
4. Don’t sit there _______ nothing. Come and help me with this table. (2006 湖北，34)
A. do B. to do C. doing D. and doing