关注微信公众号《课帮忙》查题 关注微信公众号《课帮忙》查题 关注微信公众号《课帮忙》查题 关注微信公众号《课帮忙》查题 关注微信公众号《课帮忙》查题 关注微信公众号《课帮忙》查题 公告：维护QQ群：833371870，欢迎加入！公告：维护QQ群：833371870，欢迎加入！公告：维护QQ群：833371870，欢迎加入！ 2022-06-01 Travel in the air. Travel in the air. 答案： 查看 举一反三 I usually travel to China ______ air. (travel)（）by train is much cheaper than by air. I usually travel to China ______ air. A: in B: on C: by The pressure of pilot air is usually （） than that of starting air. 词汇与结构 Warm air is less dense than cool air, and _____ air is less dense than dry air.
