Nowadays,PM2.5pollutionisbecoming

问题详情：

 Nowadays, PM 2.5 pollution is becoming _________ in China. Everyone must help to fight against it.

        A) seriouser and seriouser          B) more and more serious

        C) more serious and more serious    D) more serious and serious

【回答】

B

知识点：形容词比较级

题型：选择题