-Ididn'tseeyouatthebeginningofthepartylastnight.  -I

問題詳情：

 - I didn't see you at the beginning of the party last night.

   - I _____ on my biology report at that time.

      A. worked     B. work .       C. was working  D. am working

【回答】

C

知識點：動詞時態

題型：選擇題