The first scene of the play presents the exposition --- the main themes and characters are introduced.We are introduced to Antonio, the merchant of Venice, but find him to be sad and despondent.A conversation is taking place between Antonio, Salarino and salanio. Antionio's friends try to guess the reason for such uncharacteristic sadness, but Antonio is unable to help them understand the reason, for he says, he himself does'nt know what afflits him --- he compares his melancoly to an unknown disease that he has caught.
The main significance of this scene is that --- the main themes and characters of the play are introduced.

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