下列日常生活常识，正确的是( )。

A．甲烷的主要成分是氢气
B．焚烧塑料会产生白色污染
C．棉花、涤纶是高分子有机材料
D．蛋白质是人体所需要的六大营养元素之一

Every time _____ he thought of his past, he couldn't help bursting _____.[ ]

A. when; out tears

B. that; into crying

C. which; into cry

D. /; out crying