VOA慢速英语:Chocolate Improves Memory and Heart Health

词汇讲解：

1. increase vt. 增加，增大
例句：He had the audacity to ask for an increase in salary. 
他竟然厚着脸皮要求增加薪水。 

2. involve vt.包含; 使参与
例句：What does a preliminary evaluation involve? 
初步评估涉及哪些方面呢？

3. announce vt.宣布; 述说
例句：Please announce to the children that there will be no school this afternoon. 
请通知孩子们今天下午不上课。

4. flavanol n.黄烷醇
例句：The formulas for these phenolic compounds are Epigallocatechin gallate is the main flavanol in dried green tea. 
这些酚类化合物的分子式为:表儿茶素酸酯是干绿茶中的主要黄烷醇。 

5. extract vt.提取; （费力地）拔出; 选取
例句：Data mining is to extract knowledge from information. 
资料开采是从各种资讯中获得知识。