扩大的英文：
expansion
amplify
broaden
expand
extend
enlarge
dilate
swell
multiply
ribbing
widen
escalate

参考例句：

Open up new sources of revenue.
扩大财源

The expansion of the school system
学校机构的扩大.

Localize a disturbance
抑止动乱扩大

To enlarge(widen)business relationship
扩大业务关系

The gap between the haves and the have-nots is widening.
贫富之间的差距在扩大。

It isn't a large piece of work, and needs fattening out
这不是一部大作品，还需要扩大。

Our group of friends is enlarging By leaps and Bounds
我们的朋友圈在飞速地扩大

Otherwise the gap between aspiration and reality will continue to widen with each passing year.
否则，理想与现实之间的差距逐年扩大。

An abnormal outgrowth or enlargement,such as a wart.
赘疣一种不正常的增长或扩大，例如疣

Mercerization enhances dyeability and luster of cotton materials
丝光处理扩大棉纤维的染色能力，增加纤维的光泽。

expansion是什么意思：
n. 扩大，膨胀；扩张物

It's the expansion of a river.
这是河流的延伸部分。

This is nothing but the binomial expansion.
这不过是二项展开式。

They have an expansive grassy play area.
他们有一片广阔的游乐草地。

amplify是什么意思：
v. 扩大；详述，引申；增强

vision amplifier
图像放大器

These amplify the effects of other factors.
这放大了其他因素的影响。

he amplify the matter by an example .
他举例详述了这件事。

broaden是什么意思：
v. （使）扩大，变阔，变宽，加宽

Reading and traveling broaden the mind.
读书和旅行使人开阔心胸。

Education and experience broaden his vision and understanding
教育和经历使他眼界开阔。

I fear that in broadening your mind, you have narrowed your heart.
我就怕你见识广了，心胸却变窄了。