传染病流行曲线是根据流行期间发病者的下列哪一资料绘制而成（）。
A.暴露日期
B.诊断日期
C.报告日期
D.发病日期
E.调查日期
参考答案：D
Tom's mother told him some _____ news and then he became very _____. [ ]
A. thrilled; thrilled
B. thrilling; thrilled
C. thrilled; thrilling
D. thrilling; thrilling
机车牵引力的计量单位是（）
A.KPa
B.kN
C.Kg
