题目

Elderly people who drink several cups of green tea a day are less likely to suffer from depression, probably due to a feel good chemical found in this type of tea, Japanese researchers said. Several studies have    1  drinking green tea to lessening psychological problems and Kaijun Niu, of Tohoku University Graduate School, and colleagues found people    2   70 and older who drank four or more cups of green tea daily were 44 percent   3     likely to experience depression. Green tea is widely   4    in many Asian countries,  5    China and Japan. Niu's team   6   蜜蜂是过    生活的昆虫．在一个蜂群中有三种类型的蜂：一只    ；少数    ；几千到几万只    ．像这样具有集体行为的动物，其行为属于    ，这种行为具有    、    、    的特点．