汽油发动机的热效率一般在（）之间，而柴油发动机的热效率可达（），柴油机的热效率比汽油机（）。
参考答案：20%-30%；44%；高
— How about going downtown this morning?
— Well…, it's a bit too cold outside. And ______, I've got to do some housework.
[ ]
A. someway
B. anyway
C. somehow
D. somewhat
燃烧三个条件______、______、______．
