—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　根據時間狀語“at that time”可知是表示在過去的某一時間點的動作，應該用過去進行時。故選C。

知識點：動詞時態

題型：選擇題