They think it'll be easy but they have a surprise in store.

他们以为事情容易，到时候他们会吃惊的。

《牛津词典》

I have a surprise for you!

我要告诉你一件你意想不到的事！

《牛津词典》

I have a surprise for you: We are moving to Switzerland!

我要告诉你一件意想不到的事：我们要搬到瑞士去！

《柯林斯英汉双解大词典》

The proposal was a surprise because the two companies have been on opposite sides of the debate over net neutrality.

VOA: special.2010.08.20

And what has been a surprise and pleasure to us: students have decided to commute in from as far away as Europe and Asia.

即让我们惊讶且欣喜的是：,远在欧洲和亚洲的学生,也决定赶来。

哈佛公开课 - 幸福课课程节选

And your parents say, "Oh! We have a big surprise!"

你的父母说“哦！我们给你准备了一个惊喜！”

I used to 课堂 - SpeakingMax英语口语达人

Let me know if you have a surprise when you look at your train timetables.

BBC: Pressure is on for train companies during Olympics

We just happen to have a surprise visit.

FORBES: What Was Larry Page Thinking on Yesterday's Earnings Call?

There's something that happened this week that also says a lot about where this administration is right now, and that is that we saw Condoleezza Rice and Donald Rumsfeld have a surprise--pay a surprise visit to Baghdad.

NPR: Roundtable: Rice, Rumsfeld in Iraq, 'United 93'