斜向或竖向安装的圆销应（）装入。
参考答案：由上向下
____ through Africa, the infectious disease jumping from children to adults killed 1,000 people.
A．Swept
B．Having been swept
C．Having swept
D．Sweeping
装载易碎件时放置快件底部距下落点小于（）CM。
A、30
B、20
C、10
D、5
