How should you signal the crane operator to swing?（）.
A. With both arms extended out and palms to down, move arms back and forth
B. With arm ertended downwards and forefinger pointing down,move hand in small horizontal crecles
C. Extend arm and point finger in the direction to move boom
D. Place both fists in front of the body with the thumbs pointing outward
查看答案
往复泵是依靠做旋转运动的叶轮，依次开启入口阀和出口阀而吸入和排出液体。
A. 正确
B. 错误
抗战时期把间谍传奇和爱情传奇并置为情节特点的长篇小说是徐讦的《（）》。
流行性乙型脑炎后期出现神志不清，或痴呆、失语，可用安宫牛黄丸清心开窍。
A. 正确
B. 错误
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