“A. High level modules should not depend upon low level modules. Both should depend upon abstractions.
“A. High level modules should not depend upon low level modules. Both should depend upon abstractions.
上层模块应该不依赖于下层模块，它们都依赖于抽象。
“A. High level modules should not depend upon low level modules. Both should depend upon abstractions.
上层模块应该不依赖于下层模块，它们都依赖于抽象。