重点讲解：

venture

vt. 敢于

vi. 冒险；投机

n. 企业；风险；冒险

He ventured that plants draw part of their nourishment from the air.

他试探着提出了植物从空气中吸取它们的部分养分的观点

demonstrate

vt. 证明；展示；论证

vi. 示威

They are anxious to demonstrate to the voters that they have practical policies.

他们急于向选民证明他们有切实可行的政策。

expression

n. 表现，表示，表达；表情

Language is a means for the expression of thought.

语言是一种表达思想的方式。