慢速英语:Scientists Create Method to Test Food and Drugs for Purity

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1. design vt.设计; 绘制
例句：They wanted to design a machine that was both attractive and practical.
他们想设计一种既美观又实用的机械。

2. discover vt.发现; 碰见; 撞见
例句：She discovered that they'd escaped
她发现他们已经逃跑了。

3. harmful adj.不良; 不利; 对…有害的
例句：It's believed the affair was potentially harmful to British aviation.
据信该事件可能对英国航空业造成不利影响。

4. increase vt.增加，增大，增多
例句：The population continues to increase
人口继续增长。

5. portable adj.轻便的; 手提的
例句：There was a little portable television switched on behind the bar
柜台后面有一台开着的便携式小型电视机。