一氧化碳在城市大气污染物中含量最多,约占大气污染物总量的1/3,它大部分来自( )。
A.生活垃圾 B.汽车尾气 C.建筑垃圾 D.生物垃圾
参考答案:B
During that frightening war, these foreigners fought _______ us ________ the enemy.
A.with, for
B.for, against
C.for, with
D.with, against
口播评论的种类?