搜索结果: 1-1 共查到“农学 seasonal change”相关记录1条 . 查询时间(0.093 秒)
![](http://www.firstlight.cn/upload/imgfile/201412/1/2014121102044825.gif)
BOSTON – November 19, 2014 – Each year in the Northern Hemisphere, levels of atmospheric carbon dioxide (CO2) drop in the summer as plants inhale, and then climb again as they exhale and decompose aft...