─ Could you tell me ______? ─ Yes. He ____ to the USA. A. where is he/ has been B. where he is/ has gone C. where was he/ has been D. where he was/ has gone 答案:B下表是某城市空气质量每周公报的部分内容.下列情况对表中空气质量指标不会产生影响的是( )
项目
空气污染指数
空气质量级别
空气质量描述
总悬浮颗粒
52
Ⅱ
良
二氧化硫
7
二氧化氮
24A.焚烧垃圾B.用煤和石油产品作燃料C.太阳能的利用D.汽车排放的尾气