感染力的英文：
infectivity
infectious
contagious
catching
appealing

参考例句：

Nothing is so contagious as enthusiasm.
热情是最富有感染力的。

Enthusiasm is very catching.
热情非常富有感染力。

An infectious grin
有感染力的笑

His writing style is concise and infectious.
他的文笔凝练，很有感染力。

We are influenced by his radiant optimism.
他那具有感染力的乐观主义影响了我们。

a curiously unmoving dramatic work.
一部令人不解地对观众无甚感染力的戏剧作品

Her designs have a strong visual appeal.
她的设计在视觉上很有感染力。

He expressed infectious enthusiasm to his voters.
他对他的选民表现出很有感染力的热情。

Love, happiness and tranquility are all contagious.
爱、幸福与宁静都是有感染力的。

This article has a very strong appeal,readability and high aesthetic value.
文章具有极强的感染力、可读性,同时又有很高的审美价值。

infectivity是什么意思：
n. 传染性,易传染

vehicle of infection
传染媒介物

The infection swelled his hand.
感染使他的手肿了起来。

To infect with corruption or decay.
使腐败传染腐化或腐朽

infectious是什么意思：
adj. 传染的；有感染力的

When you have this anthema you are still infectious.
身上还有这种疹子就仍然有传染性。

His writing style is concise and infectious.
他的文笔凝练，很有感染力。

To implant microorganisms or infectious material into(a culture medium.
菌体培养把微生物或传染性物质植入(培养基)

contagious是什么意思：
adj. 接触传染的；感染性的；会蔓延的

Fear can be contagious.
恐惧会感染他人。

Nothing is so contagious as enthusiasm.
热情是最富有感染力的。

The optimism of those Saturday afternoons was contagious
那些星期六下午出现的乐观精神具有感染性。