introduction的復數形式為introductions，introduction為可數名詞。例句：She was punctilious in the matter of introductions.她在介紹別人時總是舉止得體。

Introduction用法例句

1.The camera has undergone only two minor tweaks since its introduction.

這款相機自推出以來僅進行過兩次小的改進。

2.Millions of words have been written about the introduction of the euro.

有關采用歐元的文章數不勝數。

3.I tutored a two-day Introduction to Chairmaking course at the college.

我在那個學院教過為期兩天的椅子制作入門課。

4.A prolonged drought had necessitated the introduction of water rationing.

由于持續干旱，有必要對用水實行配給了。

5.the introduction of student loans

學生貸款的推行

不可數的抽象名詞

freedom自由

laughter笑

wealth財富

poverty貧困

responsibility責任