—Mum, my little sister is crying all the time.

—Mary, be _____! She feels sick. You should take good care of her. [ ]

A. patient        

B. lazy            

C. polite          

D. fair

人工费定额根据集团公司确定的劳动定额标准和工作物单价进行测算，人工费定额不随不同的生产环境和条件进行浮动调整。