如图所示是水的电解实验。该实验的主要目的是
A.观察水分解的现象
B.研究水分解产物的性质
C.探究水分解的条件
D.验证水是由氧元素和氢元素组成的
答案:D
He looked incredulous(不轻信的) on hearing the news. He seemed to think it _____.
A. incompatible B.incredible C.inclusive D indifferent
轴心受力构件选型时注意哪些方面?