Just as on smoking, voices now come from many quarters insisting that the science about global warming is incomplete, that its OK to keep pouring fumes into the air until we know for sure.

　　【析句】本句的主干是voices now come from many quarters，現在分詞短語insisting 作伴隨狀語，后面是兩個以that 引導的賓語從句，

　　其中第二個賓語從句還包含以until 引導的時間狀語從句。

　　答案：

　　就同吸煙問題一樣，來自許多領域的聲音堅持認為有關全球變暖的科學研究還不完整，在我們確定此事之前向大氣中繼續排放廢氣是沒問題的。