VOA慢速英语:Seeking a Better Way for African Farmers to Fight a Fever

短语讲解：

1. A parasite is an organism that feeds on other organisms.

feed on以…为食,以…为能源
例句：Squirrels feed on nuts.
松鼠以坚果为食。

2. Then they treat them with drugs to help them recover.

treat with对待; 和…商谈; 用防护措施处理某物
例句：This was the first time I had been treated with such respect.
我是第一次受到这样的礼遇。

3. Once a cow is infected with this parasite, all the data indicates that the cow stays infected for life.

be infected with感染,沾染上
例句：The man has been infected with cholera.
这人已染上了霍乱。

4. And the consequences of that, the big deal about that is, that means that cow, even a cow that has been vaccinated, now it’s protected against the disease, but it can still transmit.

protect against保护, 保卫
例句：You need warm clothes to protect you against the cold.
你需要暖和的衣服来御寒。

5. And that adds to the cost of it, and also adds to the difficulty of using it in places like Africa.

add to增加, 加强
例句：The snowstorm added to our difficulties.
暴风雪增加了我们的困难。

6. The study is aimed at developing a new vaccine for the East Coast fever parasite.

aim at (以…)瞄准; 针对, 以…为目标
例句：The visit was aimed at expanding the relations between the two countries.
访问的目的是扩展两国的关系。