题目

According to recent report, one of the rare animals,        crocodile, will be in anger of dying out in       2020s    A. a, /                     B. /, the                        C. the, /                        D. the, the 答案：DMore and more people have a low-carbon life and the air is getting much ________ than a few years ago.A. clean B. cleanest C. cleaner D. the cleanest