The boat drifted along on the sea for a good hour （）it was safely anchored at the dock.
A、
before
B、
when
C、
after
D、
while
【正确答案】：A
【题目解析】：
句意：船在海上漂流了一个小时，才安全地停靠在码头。根据句意，船漂流发生在停靠在码头之前，故用before。
The boat drifted along on the sea for a good hour （）it was safely anchored at the dock.
The boat drifted along on the sea for a good hour （）it was safely anchored at the dock.
before
when
after
while
句意：船在海上漂流了一个小时，才安全地停靠在码头。根据句意，船漂流发生在停靠在码头之前，故用before。