题目

处于生长发育阶段的青少年适当多吃点富含蛋白质的食物，这是因为蛋白质（ ） A . 能加速血液循环 B . 是人的生长和细胞更新的重要原料 C . 能预防脚气病 D . 是人体生命活动最主要的供能物质 答案：BHe kept a notebook, in which ______ the telephone number and email addresses of his friends.     [      ]A. wrote          B. have written       C. was written          D. were written