一个圆柱的底面半径扩大2倍，则它的侧面积扩大4倍．______．
圆柱底面半径扩大2倍，高不变，侧面积就扩大2倍．
故答案为：错误．
I can't remember when I first met Mrs White, but I am sure it was________Sunday because everyone
was at________church.[ ]
A. /; a
B. the; /
C. /; the
D. a; /
下列哪项引起左室容量负荷过重（）.
A.二尖瓣狭窄
B.二尖瓣关闭不全
C.肥厚型心肌病
D.主动脉瓣狭窄
E.肺动脉高压
