Nowadays,PM2.5pollutionisbecoming

問題詳情：

 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

知識點：形容詞比較級

題型：選擇題