【单选题】电机正反转运行中实现电气联锁的方法是将两个接触器的常闭触头( )联在对方的线路中。
【简答题】阅读下列信息,回答有关问题 “××雪饼”的包装袋内常放有一包干燥剂,干燥剂袋上的部分文字如图所示: (1)生石灰能作干燥剂,请写出有关化学方程式:______. (2)请勿食用是因为干燥剂食用后对人体有______作用,且该干燥剂溶于水后会______热. (3)生活中,鲜鸡蛋在进行呼吸作用时会通过鸡蛋壳表面的大量的微小孔隙呼出二氧化碳而使鸡蛋变质,为了停止鸡蛋的呼吸作用达到保鲜的目的,人们常把鸡...
【简答题】短文填空 A young couple moved into a new neighborhood. The next morning, they 1 (eat) breakfast, when the young wife saw her neighbor hang the wash outside. “That laundry is not very clean,” she said to h...
【简答题】“××雪饼”的包装袋内常放入一小包干燥剂,干燥剂袋上的部分文字如图,请仔细阅读并回答下列问题: (1)这包干燥剂的主要成分吸水的过程中,发生反应的化学方程式是:______; (2)“请勿食用”是因为干燥剂吸收水后具有______; (3)如果误食入口,应该______.
【简答题】Two thieves came to a house to steal something. They dug a hole in the wall of the house. One of them crawled ( 爬 ) into the house while the other waited outside. There lived a couple in the house. Ju...
【单选题】When the couple saw the fire star in their house, Susan tried to get in the door; _____, her husband tried to climb in through the window.
【单选题】在袋装饼干的包装中,常装有一小包干燥剂,该干燥剂的主要成分可能是
【判断题】市场专业化型这种模式可最大程度降低成本。( )
【单选题】袋装饼干的包装中,常装有一包干燥剂,该干燥剂的主要成分是
【单选题】根据化学常识,判断下列说法正确的是( )
C.
某雪饼包装中有一小袋干燥剂,其主要成分是CaCO 3