问题
单项选择题
I don't want you()your brains about such problems.
A.being always bothered
B.always to be bothered
C.to be always bothering
D.to be always bothered
答案
参考答案:C
I don't want you()your brains about such problems.
A.being always bothered
B.always to be bothered
C.to be always bothering
D.to be always bothered
参考答案:C
A、B、C、D均为短周期元素,他们在周期表中的位置如图所示.已知:B元素是地壳中含量最多的元素,它的一种单质,能供给呼吸、支持燃烧.
A | B | |
C | D |
(2)B元素形成的两种单质的分子式为______、______.
(3)C的原子结构示意图为______.
(4)D的最高价氧化物对应的水化物的分子式为______.