下列4种物质熔沸点由高到低排列的是__________。 ①金刚石(C—C) ②锗(Ge—Ge) ③晶体硅(Si—Si) ④金刚砂(Si—C) 答案:解析:原子晶体的共价键键能越大,熔沸点越高,C—C>Si—C>Si—Si>Ge—Ge。 答案:①④③②_________as one of the most important inventions of the time, the computer helps people living in different countries to do a lot of things.A.Knowing B.Known C.To know D.Know