問題補充：
單選題
________ Pierre began to help his father with the farm work when he was A.In 1980’s; his teensB.At the 1980’s; the teensC.In the 1980s; in his teensD.In 1980’s; in the teens
網(wǎng)友答案：
熱心網(wǎng)友 1樓
C解析“在二十世紀八十年代” In the 1980s，“在某人幾十多歲時”in sb’+歲數(shù)名詞的復數(shù)，所以
