your homework yet?-- Not yet. I it.A. Have you done; am doingB. Did you do; am doing

问题补充：

-- your homework yet?

-- Not yet. I it.

A. Have you done; am doing

B. Did you do; am doing

C. Have you done; did

D. Did you do; did

答案：

A. Have you done; am doing

B. Did you do; am doing

C. Have you done; did

D. Did you do; did

解析：考查动词时态。句意 你做完作业了吗？没有，我正在做。haven done 强调还没有做这个概念， 而 am doing 是说马上要做，口语中常说的（这时现在进行时表将来的概念，例如Im coming. Im going to school），所以选A项。