取一小块氢氧化钠固体置于蒸发皿中，隔一段较长时间后滴加稀盐酸

取一小块氢氧化钠固体置于蒸发皿中，隔一段较长时间后滴加稀盐酸，可以观察到的现象是（）

A. 有白色沉淀 B. 有气泡放出

C. 有白色沉淀，同时有气泡放出 D. 看不到明显变化

答案

相关题目

_____ his father came back from work_____ his homework.A.Not until; he did

_____ his father came back from work_____ his homework.A.Not until; he did B.It wasn't until; when he didC.It was until; that he didn't do D.It wasn't until; that he did

如图18(甲)所示,长为、相距为的两块正对的平行金属板和与一

如图18(甲)所示,长为、相距为的两块正对的平行金属板和与一电源相连(图中未画出电源),、为两板的右端点.两板间电压的变化如图18(乙)所示.在金属板、

酒精测试仪用于对机动车驾驶人员是否酒后驾车及其他严禁

酒精测试仪用于对机动车驾驶人员是否酒后驾车及其他严禁酒后作业人员的现场检测，它利用的是一种二氧化锡半导体型酒精气体传感器. 酒精气体传感

—May I remind you that Mr. White is waiting outside, Mrs. Green? —Oh, I _

—May I remind you that Mr. White is waiting outside, Mrs. Green? —Oh, I _________ all about it. A. forget B. had forgotten C. forgot D. was fo

通常状况下，将CO和O2的混合气体200 mL置于密闭容器内点燃，

通常状况下，将CO和O2的混合气体200 mL置于密闭容器内点燃，再恢复到原状况，气体的体积变为150 mL，则原混合气体中CO的体积可能是 A.100 mL

Ten years ago the population of our village was _______ that of theirs . A. as

Ten years ago the population of our village was _______ that of theirs . A. as twice large as B. twice as large as C. twice as much as D. as twice much as

欧阳修上书说“京城今有雕印文集二十卷，名为《宋文》者

欧阳修上书说“京城今有雕印文集二十卷，名为《宋文》者，多是当今议论时政之言……祥其语言，不可流布，而雕印之人，不知事体，窃恐流布渐广

7．下列句中加横线词的解释，正确的一项是（） A．

7．下列句中加横线词的解释，正确的一项是（） A．六艺经传皆通习之六艺：礼、乐、射、御、书、数 B．

取一小块氢氧化钠固体置于蒸发皿中，隔一段较长时间后滴加稀盐酸

答案

相关题目

最新题目