— Would you go to the concert this evening?

— Sorry. ________ tomorrow's lessons, I have no time to go out with you.[ ] 

A. Not preparing  

B. Not having prepared

C. Not to prepare  

D. Being not prepared

（）是指企业对内部控制建立与实施情况进行监督检查，评价内部控制的有效性，发现内部控制缺陷，应当及时加以改进。

A.风险评估

B.控制活动

C.信息与沟通

D.内部监督