本题目来源于试卷: Photochemical Smog，类别为 IB环境系统与社会
[单选题]
Identify the stateme:a p-)e/ppgi yr9t r.;lz2:3axpc tsk nt(s) that are not true abouxhs6 yvm:a5o - pkdg:-t primary pollutants.
I.
Released directly from a source into the environment
II.
Usually more toxic than secondary pollutants
III.
Formed when pollutants combine under certain environmental conditions
A. I only
B. II only
C. I and III only
D. II and III only
参考答案: D
本题详细解析:
Primary pollutants are released directly from a source such as CO2 from a 2sm vwa tuqv u *7mjd.ib 9.*/qqf:du4car.
Secondary pollutants form when primary pollutants combine with other pollutants in the environ:qsm wu4.dvvb7 u29qi/tudqamf j *.*ment.
Secondary pollutants tend to be more toxic. For example ground level ozone or acid deposition.
| 
