I don't know that off the top of my head
這個(gè)問題我現(xiàn)在一時(shí)想不起來。
I can't answer your question off the top of my head.
我現(xiàn)在一時(shí)回答不了您的問題。
I can't comment on that off the top of my head.
我現(xiàn)在一時(shí)無法對此發(fā)表評論。
Perhaps can I get back to you on that later?
或許我可以過一會兒再回答您的問題?
Perhaps can I talk about that later?
或許我可以晚一點(diǎn)再談這個(gè)問題?
Perhaps can I deal with that later?
或許我可以遲一些再處理這個(gè)問題?