VOA慢速英语:Regulators Tell Farmers to Stop Using Some of The Drugs on Livestock

1.This makes antibiotics less effective when they are used to fight diseases in humans.

be used to v.习惯于，适用于;  
例句：Yet computing can also be used to tackle climate change.
然而，计算机同样也能用于解决气候变化问题。

2. The decision by the FDA to ask rather than order the drug companies to make the changes has angered some activists.

rather than （要）…而不…，与其…倒不如…; instead of sb/sth 而不是;
例句：Passions are inflamed rather than cooled.
激情被点燃而不是冷却。

3. He says there is a lack of good information on the amounts of antibiotics used on farms, as well as by doctors.

a lack of 缺乏，缺少;
例句：The second is a lack of political co-ordination.
第二方面是欧洲各国之间缺乏政治协作。