He became an actor at a very young age but it was nearly 20 years ______ he became famous.
A. until B. when C. before D. that
He became an actor at a very young age but it was nearly 20 years ______ he became famous.
A. until B. when C. before D. that
C 句型：It’s /will be +时间段 before +从句：过了多久才……