Question

---You look tired.

---Yes. I ________ without rest until twelve o'clock.

1. A.
   am working
2. B.
   was working
3. C.
   has worked
4. D.
   had worked

Answer 1

B
本題考查時(shí)態(tài)。由句中“直到十二點(diǎn)為止”可以判斷，這是描述與現(xiàn)在時(shí)間無關(guān)的過去動(dòng)作，用過去進(jìn)行時(shí)。