Seriously though, it could be really dangerous.

不过说实在的，这事说不好真的很危险。

《牛津词典》

Their parents don't allow them to swim in the river because it's really dangerous.

他们的父母不允许他们在河里游泳，因为那真的很危险。

youdao

This can be really dangerous because there are harmful chemicals in the smoke from both wood and coal and they can seriously pollute the air in your home.

这是非常危险的，因为木材和煤炭产生的烟雾中都含有有害的化学物质，会严重污染家里的空气。

youdao

Jack White has described the sound as "really dangerous and abrasive."

VOA: special.2009.08.07

Boy, in this political season, that's a really dangerous phrase to use, right?

嘿，在这个政治的时代里，这个词儿很危险，是不？

麻省理工公开课 - 计算机科学及编程导论课程节选

Yeah, driving in LA, it's really unpredictable and can be dangerous.

是的，在洛杉矶开车，真的没法预测，可能很危险。

利用大众交通工具吧 - SpeakingMax英语口语达人

And when something dangerous, really dangerous like Sandy, comes along they have to shout louder.

FORBES: How A Facebook Page Prepared A Region For Hurricane Sandy, And What That Teaches About Social Media

"There is in this region a really dangerous group of loggers, " Hilario Lopes Costa from the CPT told the Associated Press.

BBC: Brazil Amazon: Sixth murder since May amid land rows

"It is really dangerous when religious leaders come out and try to tell us exactly what God is up to, " he says.

NPR: Christian Leaders Balk at Robertson's Remarks