请各位英语高手帮忙分析一下这个句子，主语谓语是什么，还有动名词不是不可以作谓语么

楼上，不定式是可以做主语的 你说错了 ！

这个句子是错的，
楼主的句子根本就没抄完整，楼主啊，我是说怎么看不懂（也不知道一楼的怎么改的出来）！！这是一个2005年八月的托福题。
原句是：
Drinking water containing excessive amounts of fluorides causes the enamel of teeth to become brittle and to chip off, leaving a stained or mottled effect.

Drinking water 是主语；containing excessive amounts of fluorides 是现在分词做后置定语，修饰water；causes做谓语；enamel of teeth是宾语；to become brittle and to chip off是不定式做宾语补足语，用了平行结构；leaving a stained or mottled effect是现在分词做结果状语

楼上，不定式可做主语，它只是不可以做谓语罢了，不要误人子弟谢谢，个人愚见整个句子无谓语动词....

主语：drinking water
to do为不定式不可作主语
改：Drinking water containing excessive enamel of teeth becomes brittle and chips off,leaving a stained or mottled effect