题目内容
I don't know _____ they have kept in touch with me by writing letters since last year.
[ ]
A.what
B.how long
C.why
D.when
答案:
解析:
解析:
|
why 在从句中作原因状语. |
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题目内容
I don't know _____ they have kept in touch with me by writing letters since last year.
[ ]
|
why 在从句中作原因状语. |