用碘治疗甲状腺功能亢进症，最常见的并发症是（）

A.甲状腺癌变

B.血小板减少

C.甲状腺功能减退症

D.甲状腺功能亢进危象

E.白血病

Steve gets on the elevator at the 11th floor of a building and rides up at a rate of 57 floors per minute. At the same time Joyce gets on an elevator on the 51st floor of the same building and rides down at a rate of 63 floors per minute. If they continue traveling at these rates, at which floor will their paths cross

A．19

B．28

C．30

D．32

E．(E) 44