Mary had finished her homework ____ the time I got home.A.until B.by C.aMary had finished her homework ____ the time I got home.A.untilB.by C.at D.when

Mary had finished her homework ____ the time I got home.A.until B.by C.aMary had finished her homework ____ the time I got home.A.untilB.by C.at D.when
Mary had finished her homework ____ the time I got home.A.until B.by C.a
Mary had finished her homework ____ the time I got home.
A.until
B.by
C.at
D.when

Mary had finished her homework ____ the time I got home.A.until B.by C.aMary had finished her homework ____ the time I got home.A.untilB.by C.at D.when
by the time 在什么时间/时候

答案： B
翻译： 玛丽在我到家时已经做完了作业

B
Mary had finished her homework by the time I got home.