在同一开采范围内不得重复颁发煤炭生产许可证。
参考答案：对
暴露组与非暴露组医院感染率之比称为（）
A.相对危险度
B.医院感染患病率
C.罹患率
D.医院感染发病率
E.比值比
.He had a bad week. He lost his job, ________ ,his car was stolen.
A．on top of that
B．on top of it
C．and on top of which
D．on top of which
