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Please state your opinions clearly.
Literal
Clearly [adverbial-と] opinions [object-を] say [request-ください].
はきはき is a 擬態語 (state mimetic) meaning 'clearly / briskly / articulately' — describing a manner of speaking that is direct, confident, and well-articulated. The adverbial と after it marks it as modifying the verb 言う. ~てください is the standard polite request form. A common instruction in educational or workplace settings where clear communication is valued.