题目

下列4种物质熔点沸点由高到低排列为________（填序号） ①金刚石（C—C）②锗（Ge—Ge）③晶体硅（Si—Si）④金刚砂（Si—C） 答案：①＞④＞③＞②-Excuse me, can you tell me the way to the nearest railway station？-Sorry, I don’t know. I’m new in a town. This is my time here.A.first B.second C.third