abbr.(缩)上午,午前;
例句:
The child's birth occured at 2 a.m.
这孩子凌晨两点出生.
The time appointed for the mass meeting was 9 a.m.
群众大会上午9点届时召开.
Bus service starts at 5 a.m.
公共汽车早上五点出车.