单项选择题
A.插入异常 B.删除异常 C.数据冗余太大 D.插入异常、删除异常、数据冗余太大
CDU的全称是Combing&（） Unit。
填空题CDU的全称是Combing&（） Unit。
（）terrible weather we’ve been having these days！
填空题（）terrible weather we’ve been having these days！
It was about 600 years ago （） the first clockwith a fac...
填空题It was about 600 years ago （） the first clockwith a face and an hour hand was made.
