下列实验基本操作正确的是 A.点燃酒精灯 B.倾倒液体 C.量取液体 D.检查气密性
Today, housework has been made much easier by electrical _____. A. facilities B. appliances C. instruments
设NA为阿伏加德罗常数的值,下列叙述中正确的是 A.0.1 mol/L MgCl2溶液中Cl-离子数为0.2 NA B.19.2 g铜与足量的稀硝酸反应产生NO的体积为4.48 L C.46 gNO2和
患坏血病是因为人体中缺乏A.维生素A B.维生素B C.维生素C D.维生素D
若||=8,||=5,则||的取值范围是( ) A.[3,8] B.(3,8)C.[3,13] D.(3,13)
下图为某地区城市规划图,据图回答1-3题。 1.从城镇规划来看,该地区的地形最有可能是 ( ) A.平原 B.山区 C.高原 D.丘陵 2.图中信息
—Jack,it seems that you like to work with animals. —Yes,I think animals _____as our friends. A. should be regarded B. should regard C. were regarded
一种熔融碳酸盐燃料电池原理示意如图。下列有关该电池的说法正确的是( ) A.反应CH4+H2O3H2+CO,每消耗1molCH4转移12mol 电子 B.电极A上H2参与的