影响血压的因素有（）。
A.心输出量
B.心率
C.动脉管壁的弹性
D.血量/容量比值
E.外周阻力
参考答案：A, B, C, D, E
The president, together with his bodyguards, ____ to the nuclear station ___ there was an accident
20 minutes ago. [ ]
A. have come, which
B. came, in which
C. has come, where
D. came, in where
钢管存放的场地应平整，场地应无大石块、地上无积水，存放场地应保持（）坡度。
A.1%
B.2%
C.3%
D.4%
