下列哪项不是脑瘫发生的危险因素（）
A.孕龄34～36周
B.低体重（<2500g）
C.胎盘早剥
D.胎儿畸形
E.胎儿窒息
参考答案：A
圆锥的底面半径扩大2倍，高扩大2倍，体积扩大______倍．
--- What are the workers talking about ?
--- They are discussing the idea the old worker ______ at the meeting yesterday.
A．put forward
B．came up
C．set off
D．brought out
