Question

【題目】The teacher came into the classroom while the students _________ their homework.

A. are doing B. did C. were doing

Answer 1

【答案】C

【解析】

句意：當(dāng)學(xué)生們正在做作業(yè)的時(shí)候，老師走進(jìn)了教室。are doing正在做，現(xiàn)在進(jìn)行時(shí)；did做，是do的過(guò)去式；were doing正在做，過(guò)去進(jìn)行時(shí)。根據(jù)句中The teacher came into…可知，這句話用的是過(guò)去時(shí)態(tài)，且從句中表示的是正在進(jìn)行的動(dòng)作，因此應(yīng)用過(guò)去進(jìn)行時(shí)態(tài)，選C。