【简答题】目前,汽车尾气已成为许多大城市空气的主要污染源.汽车尾气中含有CO和NO等多种污染物. (1)汽车燃料中一般不含氮元素,尾气所含的NO从何而来?写出有关的化学方程式:______ (2)治理汽车尾气中NO和CO的一种方法是:在汽车的排气管上装一个人催化转化装置,使NO和CO反应,生成CO 2 和N 2 .反应的方程式是:______ (3)下列措施中,能减少或控制汽车尾气污染有效且可行的是____...
【单选题】What is the theme of "Everyday Use"?
B.
Property and identity.
C.
Lifestyles and identity.
D.
Attitudes and heritage.
【单选题】Which of the following is probably the best description of the term "Theme"?
A.
It refers to what the story is about.
B.
It is the general idea underlying the story.
C.
It is the clearly stated meaning of the story.
D.
It is the moral lesson conveyed by the story.
【简答题】vt. 把......强加给(on);采用,利用
【简答题】vt. 把......强加给(on);采用,利用