1. What do you think green house gases do?本句中think后接了一个由what引导宾语从句。但应注意是: 特殊宾语从句即当普通疑问句主句谓语动词是 think, believe, suppose, consider, imagine, guess 和 suggest 等时，表疑问词要放在主句前即句首。比如：
[正] Who do you think will win in the game?[误] Do you think who will win in the game?当然普通情况下宾语从句疑问词应放在主句之后，比如：[误] Why do you know we can't cut down the big tree?[正] Do you know why we can't cut down the big tree?
2 … it is a rapid increase compared to most natural changes.
1). vt. 比较；对照。                  
compare…with…表示 ...