A. 存储资料安全可靠 B. 节约存储空间 C. 存取方便、迅速 D. 逻辑合理
A. 1 B. 2 C. 3 D. 4
A. Doing it for l is 3 B. Doing it for l is 1 C. Doing it for l is 2 Doing it for l is 0 E. Doing it for l is?C1 Finish