-Excuse me. Do you have a watch?

-__________. It's time for dinner.[ ]

A. Here you are

B. Yes, I am

C. No, I don't

D. Yes. It's six o'clock

麻疹疫苗接种后血清阳转率的分母应为

A．麻疹患者人数

B．麻疹易感人数

C．获得麻疹终身免疫人数

D．麻疹疫苗接种人数

E．麻疹疫苗接种后的阳转人数