【单选题】BE025杌车燃油的()高,则燃油着火较快,柴油机工作柔和。
【单选题】对于柴油机的燃料,说法错误的是?
A.
柴油的十六烷值高,发火性好,可有效缩短着火延迟期,对减小燃烧噪声非常有利。
B.
柴油的馏程(馏出温度)低,蒸发性好,容易形成高质量的混合气,燃烧速度快,且易于完全燃烧,对提高柴油机的热效率和降低排气污染有利。
C.
碳原子数较多、分子量较大的烃类,十六烷值较高,但蒸发性较差
D.
碳原子数较少、分子量较小的烃类,蒸发性较好,但十六烷值较高
【判断题】考虑到十六烷值对发动机燃烧的影响,当其值较高时可推迟喷油以降低氮氧化物的影响。
【单选题】患了癌症
D.
one’s lifelong passion for…
F.
emotionally draining and physically dangerous missions
G.
raise world awareness of wars and droughts
【单选题】分担责任
D.
one’s lifelong passion for…
F.
emotionally draining and physically dangerous missions
G.
raise world awareness of wars and droughts
【单选题】以身作则
D.
one’s lifelong passion for…
F.
emotionally draining and physically dangerous missions
G.
raise world awareness of wars and droughts
【简答题】2 Replace the underlined phrases with a
single word that has the same meaning. ► They were physically trying to hurt each
other . fighting 1 They were the men we fought against .
____ 2 ...
【简答题】立方晶系中指数相同的晶面和晶向有什么关系?