Question

.Jane is back in May ,by____the new house should be finished. A.which B.that Cwhom D when

Jane is back in May ,by____the new house should be finished. A.which B.that Cwhom D when 选D when
they settled in Seattle,by when she had obtained a master's degree in economics
为什么用when 为什么

Answer 1

by when 应该和by the time是一样的，在......之前。两句都用来引导时间状语从句

Answer 2

May是五月份的意思，是时间，BY 后面就要跟when,在......之前, 引导时间状语从句啊。
这要看句子的意思，前面强调的是时间，就要跟when

Answer 3

by when 引导一个非限制性定语从句

Answer 4

定语从句，