profit

1.profit作“益处”解前面不可加a，也没有复数形式profits。说“利润”用profit，a profit和profits都可以。例如：We hoped to sell the goods at a profit.和Part of the profits were devoted to charity.

说“利得税”用profit tax或profits tax都可以。

2.profit from, profit by和profit of都作“利用”或“得益于”解，profit from最普通，似乎在动名词前面总是用profit from。例如：

• She profited from（或by，或of）this time to look at the paintings.
• She profited from looking at the paintings.