It can be inferred from the first paragraph that _____.
Đáp án C
Air pollution requires a very flexible definition that permits continuous change.
If your shoes are not waterproof and if you aren’t (5)_________ for the cold, you might look good, but feel terrible!
The word 'current' in line 7 could best be replaced by which of the following?
Domestication of plants and animals probably occurred because of ________.