We need a clear understanding of the problems involved.

　　我們需要了解清楚所涉及的各種問(wèn)題。

　　I don't know what you're on about.

　　我不懂你在談什么。

　　The situation was more complicated than they had at first realized.

　　形勢(shì)比他們最初意識(shí)到的更為復(fù)雜。