UML's use case diagram arrow direction

UML Case Diagram (use cases) arrow direction:

Always forget the direction of the arrows, provoke jokes.

1, association, no arrows, actor connection usecase can;

2, Directedassocition,actor connection UseCase, arrow by actor point to usecase (role point use case);

3, generalization, inherit, I read it as " inherit in ", of course, the arrows point to the father;

4, Dependency, I read " depends on", I know the direction of the arrow;

5, include, I read as " contained ", the arrow by the inclusion of the person is pointed to the inclusion;

6, Extend, I read as " extended to " or " extended from ", the arrow from the extended "sub" point to its "parent";

Summary: In addition to including the direction, the others are "small" point to "big", "child" point to "parent", "General" point to "abstract".

UML's use case diagram arrow direction