相关Howisthesmogcontrolg的文学知识

问题详情： —Howisthesmogcontrolgoingoninourcapitalcity?—Itcouldn’tbeworse.You________believeBeijingupgradedthesmogalertfromyellowtoorangeandthenredagainyesterday.A.won’t B.mustn’t C.needn’t D....