Professor Smith, along with his assistants,______ on the project day and night to meet the deadline.

A．work

B．working

C．is working

D．are working

各级市场监管部门应根据监管对象的（）和（）分类，注重运用大数据手段，完善事中事后监管措施，为市场主体提供便利化服务。

A.诚信记录

B.信用等级

C.信用记录

D.信用评价