下图是实验室中氧气的制备、收集、验满、验证性质的操作,其中

 

下图是实验室中氧气的制备、收集、验满、验证性质的操作,其中正确的是 (     )

答案

A

相关题目

Each time tourists travel to Beijing, they_______ the Forbidden City.A.will be
Each time tourists travel to Beijing, they_______ the Forbidden City.A.will be shown upB.will be shown aroundC.will show aroundD.will show to
有四种粒子的结构示意图,下列说法不正确的是(   )  
有四种粒子的结构示意图,下列说法不正确的是(   )       ①               ②              ③                  ④ A.
Books are made __________ paper while paper is mainly made __________ wood.A.o
Books are made __________ paper while paper is mainly made __________ wood.A.of; ofB.from; fromC.of; fromD.from; of
Mrs. King put a coat ________ the sleeping girl to keep her warm.      A.
Mrs. King put a coat ________ the sleeping girl to keep her warm.      A. over       B. with            C. behind             D. beside
下列关于细胞核的说法,不正确的是 A.所有的真核细胞均有
下列关于细胞核的说法,不正确的是 A.所有的真核细胞均有细胞核    B.细胞核是遗传物质贮存和复制的场所 C.DNA主要存在于细胞核内       D.细胞
设向量a=(-2sinα,2cosα)(0<α<π),向量b=(-,0),则a·b的夹角是 A.α
设向量a=(-2sinα,2cosα)(0<α<π),向量b=(-,0),则a·b的夹角是 A.α               B.π-α                  C.|-α|               D.-α
At a laboratory in Germany ,volunteers slide into a machine and perform simple t
At a laboratory in Germany ,volunteers slide into a machine and perform simple tasks, such as deciding whether to add or subtract two numbers , or choosing which of two buttons to press. They have no
28.人体细胞中组成核酸的五碳糖、碱基和核苷酸种类依次是
28.人体细胞中组成核酸的五碳糖、碱基和核苷酸种类依次是 A.2   4   4                   B.4   4   4    C.2   8   8         

最新题目