下列分子晶体:①HCl ②HBr ③HI ④CO ⑤N2 ⑥H2熔沸点由高到低的顺序是 [ ]
A.①②③④⑤⑥
B.③②①⑤④⑥
C.③②①④⑤⑥
D.⑥⑤④③②①
答案:C
We can't continue to pretend that the problem of homelessness doesn't________in this city. [ ]
A. exist
B. live
C. be
D. survive
随着新大陆的发现和英国的殖民扩张,西餐在全球范围得到发展。西餐传入中国的时期是()。
A.郑和下西洋之后
B.鸦片战争之后
C.戊戌变法之后
D.新中国成立之后