第18题: [单项选择]ChineseauthoritiessaidTuesdaytraceamountsofatmospheric()fromJapanhavebeendetectedinBeijingandmanyareasotherthanHeilongjianginthenortheastbutstressed(强调)theyposenothreattopublichealth. A. radial B. radiate C. radiator D. radiation 参考答案:D 答案解析: