冬卵
参考答案：
也叫滞育卵、休眠卵，卵外有厚的棕色硬壳，胚胎发育过程中有滞育现象，需特殊的滞育终止处理才能发育成无节幼体。
My friend has returned from the UK. She ______ at Oxford for four years, during which we communicated with each other on the Internet.
A．studied
B．has studied
C．had studied
D．has been studying
有关产褥期的处理，下述哪项错误
A．每日用1:5000高锰酸钾液体擦洗会阴
B．肝炎患者不可用大量雌激素退奶
C．产后子宫复旧不良者给予子宫收缩剂
D．产后排尿困难者常规导尿
E． * * 皲裂可局部用蓖麻油铋糊剂
