整个伤寒病程中阳性率均不高的是:()
A.骨髓培养
B.血培养
C.尿培养
D.大便培养
E.肥达反应
参考答案:C
I'm tired out. I ______ all afternoon and I don't seem to have finished anything.
A. shopped B. have shoppedC. had shopped D. have been shopping
(1)a3•am•a2m+1=a25(a≠0,1),求m的值.
(2)已知(a+b)a•(b+a)b=(a+b)5,且(a-b)a+4•(a-b)4-b=(a-b)7(a+b≠0,1;a-b≠0,1),求aabb的值.