What relation (of one type only) exists between Actors?

Which type of relationship is not represented in this diagram?

(multiple answers)

Which of the following features are not considered to be concrete and complete?

(multiple answers)

What is FALSE about use case diagrams?

(multiple answers)

Which actor is responsible for UC15 „Diagnose vehicle” case?

What is true about the relationship between UC16 „Repair vehicle” and UC19 „Inform: Part not available...” case:

(multiple answers)

In which of the following use cases is there an „extension point”?

(multiple answers)

What is true about the relationship between UC18 „Return the vehicle to the garage” and UC2 „Register a New Repair” case:

The singleton pattern is an example of a pattern from the group:

1. If you want to use an existing class but its interface does not match the one you need.

or

2. When you want to create a reusable class that interacts with unrelated or unknown classes (that is, those that will not necessarily have interfaces compatible with the class you are expanding).

you will apply