'An immediate reply of yes or no'.

'立即回答是或否'。

With regard to your request, I'm afraid I can't give you an immediate reply.

关于你的请求，我恐怕无法马上给予答复。

His hand was steady, but the attitude was an excuse for not making an immediate reply.

他的手很稳， 但这种态度是没有立即回复的借口。