我国制定大气卫生标准的原则是

SO对健康影响是

A:与可吸入颗粒物共存，其毒性大大增强 B:主要作用部位是上呼吸道 C:吸附SO的颗粒物是变态反应原 D:可以增强BaP的致癌作用 E:哮喘患者对SO更为敏感 F:主要来源于硫酸厂

Since he was busy, so he didn't come.（）

A:Since B:was C:so D:didn't

Stop making so much noise （　）_ the neighbor will start complaining.

A:or else B:but still C:and then D:so that

Stop making so much noise（）the neighbor will start complaining.

A:or else B:but still C:and then D:so that

Stop making so much noise ______ the neighbor will start complaining.

A:or else B:but still C:and then D:so that

—How did the plan strike you —It _____, so we can’t think too highly of it.

A:all depends B:makes no sense C:is so practical D:is just so so

—How did the plan strike you
—It （　）, so we can’t think too highly of it.

A:all depends B:makes no sense C:is so practical D:is just so so