VOA慢速英语:In Fight Against Troubling Viruses, Vaccines Offer Hope

短语讲解：

1. The spread of the Zika virus caused public health officials in many nations to put in place strong measures to control its spread.

put in place 实施; 实现; 做到
例句：They're offended by the elaborate security measures the police have put in place.
他们被警方部署的繁复安全措施惹怒了。

2. He says that even one child affected by zika has a very big impact on community resources and a family's ability to deal with the results.

impact on 对…冲击，碰撞，影响
例句：There will be a bigger impact on America than the civil war.
对美国将有一个比内战还要大的冲击。

3. At a time when Nigeria was thought to be almost polio-free, three children were diagnosed with the virus.

at a time 依次， 逐一， 每次
例句：Can I borrow two books at a time?
我可以一次借两本书吗？