环保设备按构成可分为()
A.单体设备和成套设备
B.定型设备和非定型设备
C.通用设备和仪器设备
D.机械设备和仪器设备
参考答案:A
The photo brought me back to the memory of the time in Qingdao, _________ I spent my summer holiday by the seaside with my friends.
A.that
B.when
C.which
D.what
下列说法正确的是( )
A.任何酸与碱发生中和反应生成1 mol H2O的过程中,能量变化均相同
B.同温同压下,H2(g)+Cl2(g)=2HCl(g)在光照和点燃条件下的ΔH不同
C.已知:①2H2(g)+O2(g)=2H2O(g)ΔH=-a kJ·mol-1,
②2H2(g)+O2(g)=2H2O(l)ΔH=-b kJ·mol-1,则a>b
D.已知:①C(s,石墨)+O2(g)=CO2(g)ΔH=-393.5 kJ·mol-1,②C(s,金刚石)+O2(g)=CO2(g) ΔH=-395.0 kJ·mol-1,
则C(s,石墨)=C(s,金刚石) ΔH=+1.5 kJ·mol-1