He had already prepared his opening remark: An unexpected visitor! A very strange thing happened.

他已经准备好了开场白：一个不速之客！出了一件非常离奇的事情。

Stop monkeying around: These two girls got an unexpected visitor while posing in front of the gorilla sanctuary.

别胡闹了！这两个小女孩在大猩猩庇护所摆POSE的时候，来了一位不速之客。

The unexpected visitor spooks the children.

意外的访客惊吓了孩子们。

The unexpected visitor caused a perturbation in their daily routine.

意外的访客在他们的日常生活中引起了干扰。

In the fall of 2017, we spotted an unexpected visitor to our solar system from deep space.

2017年秋季，我们发现了一个来自深邃太空的太阳系意外访客。

Check who is at the door before opening it, and do not open the door to an unexpected visitor.

在开门前确任是谁后再开门，如有不任识或未预期的访客千万不要打开门户。