二甲醚(CH3OCH3)是无色气体,可作为一种新型能源,由合成气(组成为H2、CO、和少量CO2)直接制备二甲醚,其中主要过程包括以下四个反应: 甲醇合成反应: ①CO(g)+ 2H2(g)=CH3OH(g) △H1=-90.1 kJ·mol-1 ②CO2(g)+ 3H2(g)=CH3OH(g)+H2O(g) △H2=-49.0 kJ·mol-1 水煤气变换反应: ③CO(g) + H2O (g)=CO2(g)+H2(g) △H3=-41.1 kJ·mol-1 二甲醚合成反应: ④2CH3OH(g)=CH3OCH3(g)+H2O(g) △H4=-24.5 kJ·mol-1 ⑴Al2O3是合成气直接___has recently been done to provide more buses for the people ,a shortage of public vehicles remains a serious problem . w.w.w.k.s.5.u.c.o.m A.That B.What C.In spite of what D.Though what