根据函数的实根存在定理得到
f(1)•f(2)<0.
故选B.
— How come you are late for school again?
— ____. [ ]
A. Because I missed the bus.
B. By bus and then on foot.
C. Please excuse me.
D. It's quite wrong.
皮肤病外用药物溶液功用是
A.疳疮(硬下疳)B.杨梅疮C.横痃D.小儿遗毒(胎传梅毒)E.杨梅结毒