软产道裂伤引起出血，其出血量与下列哪些因素相关（）
A.裂伤部位
B.裂伤程度
C.裂伤时间
D.是否累及血管
E.是否因全身疾病
参考答案：B, D
The professor has received the letter ____ to give a lecture in frication Institute.
A．being invited
B．to be invited
C．inviting him
D．invited
个人不得保存应当归档的公文。 ( )
