Answer: (1) Could you read when you were four?
(2) Abeba (presumably a name)...must study hard. (Ability to do something).
(3) It might be... (uncertainty).
(4) Must have missed...( strong possibility)
(5) You must not...(making a request)
Explanation: modal verbs in any language are difficult for they usually imply the subjunctive mood - we use modals to show if we believe something is certain, possible or impossible, and, also, when we talk about ability, ask permission, and make requests and offers.