这题没问过：102
the correlation of carbon dioxide with temperature, of course, does not establish whether changes in atmospheric composition caused the warming and cooling trends or were caused by their.
请教这个by their后面省略了什么？按照其解释应该是“气候的冷暖变化”，可是他又说不能理解为waming and cooling trends or comosition.怎么回事？请指点一下。谢谢！ | 
