It'll be a long time Mr. Black back from abroad.A.before; comesB.since; has come
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It'll be a long time ________ Mr. Black ________ back from abroad.
A.before; comes
B.since; has come
C.before; will come
D.after; will come
试题答案
A
解题思路：It'll be a long time before…句型中before引导的时间状语从句用一般现在时表一般将来时．