如题所述
您好，非常高兴回答您的问题
是一种固定用法。
“to think”常用于开头，表示惊讶，意思是“你想想看（竟然）；真没想到（竟然）”。
例句：
To think of their not knowing about it!
真没想到他们对此事竟然一无所知!
To think that my sister wrote all those books and I never knew!
想想看，我姐姐写了那么多部书，我竟然一无所知！
谢谢