at the
问题描述：
at the
书上说at birth是在出生时，可是例句是were you present at the birth?而且翻译是分娩时你在场吗？这是为什么？
分娩时和在出生时有什么区别吗？
答
出生时或分娩时,根据句子语境来做出选择.He was present at the birth of the boy,这里就译为出生时,Her obstetrician（产科医生） could not be present at the birth.这里就译为分娩时.