体内羟化反应的重要供体维生素是（）
A.硫胺素
B.核黄素
C.烟酸
D.维生素C
E.叶酸
参考答案：D
据汉意或首字母的提示，填写所缺的单词。
1. Yesterday I______ (睡过头了), I was late for school.
2. Alexander Graham Bell i______ the telephone in 1876.
3. Do you know how to o______ on the machine?
4. Have you b_____ the baby's milk yet?
5. The doctor didn't ______ (披露) the truth to him.
受力钢筋同一截面的接头数量、搭接长度和焊接、机械接头质量应符合规范要求。（）
