当大气可吸入颗粒物中PM2.5为80%,而且其主要由硝酸铵和硫酸铵组成时,造成其污染的主要是()
A.木材燃烧
B.尘土扬起
C.植物微粒
D.沙尘
E.汽车尾气
参考答案:E
Now that we have settled the question of feasibility(可行性), let's proceed to the next one ─_____
raise the fund from the bank.[ ]
A. whether should we
B. that we should
C. whether we should
D. that should we
在野外对节理进行测量和观察时,应选择()、()、()的露头点。