manyknowledge可数吗

　　From them, I learn many knowledge about foreign culture.

　　从他们身上，我学到很多关于外国文化的.知识。

　　From them I learn many knowledge about foreign cultures.

　　从他们身上我学到很多关于外国文化的知识。

　　I am very like this activity very much. Because this activity can teach me many knowledge.

　　我非常喜欢这次活动，因为我能学到很多知识。