搬抬工件时注意事项有哪些？
参考答案：搬抬工件，必须两人以上，必须穿戴工鞋、工服和手套。
华北地区区别于其他地区最显著的自然特点之一是（ ）
A．雨热同期
B．黄土覆盖
C．矿产丰富
D．地势平坦
(74) systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and (75) on the disk, and controlling peripheral devices such as disk drives and printers.
A．Operation
B．Operator
C．Operating
D．Operate
