【趣谈英语】咖啡因的那些事-Caffeine Is A Natural Pesticide

Pre-Listening Vocabulary

• caffeine: a drug found in some plants, including coffee seeds and tea leaves
• pesticide¹: a substance that keeps insects or harmful materials away from a plant
• alert: awake and paying attention
• ward² off: to keep away something harmful

Caffeine Is A Natural Pesticide

 

Caffeine wakes us up and helps us stay alert. Many people rely on a caffeine kick a few times a day. In fact, coffee and tea are the most popular beverages³ in the world, making caffeine the most popular drug. Caffeine is found in the seeds, leaves, and fruit of certain plants. Have you ever wondered why caffeine exists in coffee seeds and tea leaves? Studies have shown that caffeine is a natural pesticide. It gives off a bitter odour to ward off or kill insects that come to feed on it. While caffeine is generally safe for humans, it can be toxic⁴ to pets and should be kept away from cats, dogs, and birds.

1 pesticide   

n.杀虫剂，农药

参考例句：

• The pesticide was spread over the vegetable plot.菜田里撒上了农药。
• This pesticide is diluted with water and applied directly to the fields.这种杀虫剂用水稀释后直接施用在田里。

2 ward   

n.守卫，监护，病房，行政区，由监护人或法院保护的人（尤指儿童）；vt.守护，躲开

参考例句：

• The hospital has a medical ward and a surgical ward.这家医院有内科病房和外科病房。
• During the evening picnic,I'll carry a torch to ward off the bugs.傍晚野餐时，我要点根火把，抵挡蚊虫。

3 beverages   

n.饮料( beverage的名词复数 )

参考例句：

• laws governing the sale of alcoholic beverages 控制酒类销售的法规
• regulations governing the sale of alcoholic beverages 含酒精饮料的销售管理条例

4 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。