Why abstract classes instead of interfaces?

为什么抽象类代替了接口？

youdao

The reason why Abstract Library Science has aroused suspicion lies in its unsound foundation of inner source construction, and in its lack of philosophical taste and research on concrete evidence.

“抽象图书馆学”招致置疑的主要原因是其内在资源建设的根基不牢，缺少哲学品位，缺乏实证研究。

youdao

The reason why Abstract Library Science has aroused suspicion lies in its unsound foundation of inner source construction, and in its lack of philosophical taste and research on concrete evidence.

“抽象图书馆学”招致置疑的主要原因是其内在资源建设的根基不牢，缺少哲学品位，缺乏实证研究。

youdao