Ex1

[liorlevy]

Ex1- Maya and Lior
submitted with @mayal

[robi-y]

Got it now!
Some comments:
Use case: in alternative flow, write only the varying part
Class diagram (not model, but otherwise nice modeling!): compalin => complain
Activity: I think the text "customer read answer" should be part of the decision node. It is also not clear what is the close criteria.
Sequence diagram: missing intermediate objects.
Missing deployment diagram!