Употребите глагол,данный в скобках, во временах Present Simple, Present Continuous, Present Perfect, Present Perfect

John (to work) as a top-manager.

Present Simple - John works as a top-manager every day. - Джон работает старшим менеджером каждый день.

Present Continuous - John is working as a top-manager now. -  Джон сейчас работает старшим менеджером.

Present Perfect - John has already worked as a top-manager. - Джон уже работал старшим менеджером.

Present Perfect Continuous - John has been working as a top-manager sine childhood. - Джон работал старшим менеджером с детства.