VOA慢速英语:世卫组织：发展中国家有10%的药品是假冒的

vt. 伪造; 篡改; 对…做手脚; 仿造;
vt. 假装;
n. 骗子; 冒牌货，赝品; [体] 假动作; 冒充，诈骗;
[例句]The bank manager is said to have issued fake certificates.
据说那个银行经理曾出具伪造的凭证。

hygiene

n. 卫生，卫生学; 保健法;
[例句]Be extra careful about personal hygiene.
要非常注意个人卫生。

tropical

adj. 热带的; 炎热的; 热情的;
[例句]I had deliberately picked a city with a tropical climate.
我特意选了一个热带气候的城市。

fraction

n. [数] 分数; 一小部分，些微; 不相连的一块，片段; [化] 分馏;
[例句]She hesitated for a fraction of a second before responding
她在回答之前犹豫了一下。

contaminated

v. 把…弄脏，污染（ contaminate的过去式 ）; 玷污，毒害，腐蚀（人的思想或品德）;
adj. 被污染的;
[例句]The poisons seeping from Hanford's contaminated land quickly dilute in the water.
从汉福德受污染的土地里渗出的有毒物质很快就在水中稀释了。