circulate

circulate, diffuse, disseminate, expand, extend, propagate, radiate, spread

这组词都有“延伸”“延长”“伸展”“展开”的意思。它们的区别是：
1.spread指向四面八方扩大范围。
2.circulate指无拘无束地或不间断地传播、散布到各处。例如:
She opened a window to allow the air to circulate.她打开窗户使空气流通。
3.disseminate指到处传播思想、理论等。例如:
They use the press to disseminate right wing views.他们利用报刊来传播右翼观点。
4.diffuse指光线、声音、气味等在空中传送或散布。例如:
Light diffused from the window.光从窗户射进来。
5.extend指延展物体的长度、宽度,延伸或扩大某一事物,以及延长时间、期限等,也指伸开四肢或躯体。例如:
They extended the road for three more miles.他们把那条路又延长了三英里多。
The headmaster extended our holidays by a week.校长把我们的假期延长了一个星期。
6.expand指扩大面积或体积,也指把合拢的东西放开(即三维)。例如:
This county has expanded its area under cultivation by more than 50,000 mu .该县扩大了50,000亩耕地。
Heat expands metals.热使金属膨胀。
He does exercises to expand his chest.他做体操扩胸。
7.propagate通常指宣传某种信念、看法或传播某种言论,以使更多的人相信或参与。例如:
We should not only learn knowledge, but also propagate it.我们不仅应学习知识,而且应传播它。
The Greek civilization was propagated all over Europe.希腊文明传播至整个欧洲。
8.radiate指从中心向四面八方散发,是技术用语,特指光或热的辐射。例如:
The sun radiates light and heat.太阳放射光和热。
The electric heater radiated warmth.电暖器散发出热量。