妊娠晚期反复无痛性 * * 流血的是( )
A．流产B．异位妊娠C．早产D．妊娠高血压综合征E．前置胎盘
参考答案：E
22．The site is fairly near the city center, ___ it can only be reached by a series of narrow streets．
A．and
B．but
C．or
D．So
黄河中游地区常见的自然灾害有：①凌汛、②地上河决口、③水土流失、④干旱[ ]
A、①②
B、②③
C、③④
D、①④
