Question

---I heard your grandpa used to be a teacher.
--- Yes. He was a math teacher ________.

A．on the 1950s

B．in the 1950s

C．a(chǎn)t the 1950’s

D．in 1950’s

Answer 1

B

考察年代表達(dá)。年份后面加上s，表示某個(gè)年代，故選項(xiàng)CD年代表達(dá)錯(cuò)誤。表示時(shí)間時(shí)，on表示在具體某一天，in表示在一個(gè)時(shí)間范圍。年代屬于一個(gè)時(shí)間范圍，故用介詞in，選B。