Question

black smoke from factories makes the air dirty.

black smoke from factories makes the air dirty.
make为什么要加s

Answer 1

因为主词是black smoke 属于第三人称单数， 用 makes

追问

因为black不可数对吗

追答

是smoke不可数，black黑色的是形容词

Answer 2

主语是black smoke，smoke不可数名词用三单

Answer 3

black smoke from factories makes the air dirty.
工厂的黑烟使空气变脏。