膀胱癌的危险因素有()。
A.吸烟
B.食用糖精
C.长期服用镇痛药物
D.长期尿失禁
E.长期慢性膀胱炎症
参考答案:A,B,C,E
解析:[知识点] 膀胱癌的病因病理
It is requested that each of the teachers invited ______ a performance at the party.
A.give
B.will give
C.has to give
D.must give
固相控制的意义是什么?