We have a high regard for Mr. Black because he always tries to ________ his principles. [ ]

A. live up to        

B. look forward to    

C. catch up with    

D. put up with

下列栅格数据编码方法中，接近矢量结构，不具有区域性质的编码方法是（）

A.四插树编码

B.块码

C.游程编码

D.链码