某市欲了解糖尿病在该地区的危害状况,现对该市常住人口进行普查,根据调查资料可计算出糖尿病的
A.发病率
B.患病率
C.死亡率
D.治愈率
E.病死率
参考答案:B
Mr. Wang was very poor, _____ he was very happy. [ ]
A. and
B. but
C. or
D. so
[问题2] 若采用L2TP协议,则该协议除IP协议外还支持哪几种协议