surf the Internet / Net
网上冲浪 

例句：
Some analysts¹ argue that those who spend all day surfing the Internet should pay more than those who just send the occasional e-mail message.
一些分析家指出那些整天在网上冲浪的人的花费要比那些只是偶尔发发电子邮件的人多的多。
 

heart stands still
提心吊胆；非常害怕
 
例句：
Jack's heart stood still when he saw his pet dog run into the street in front of a car.
杰克的心提到了嗓子眼儿，他看见他的小狗冲到了马路上一辆汽车的前面。

There's a possibility.
有可能。

对话：
A: Waiter, I'm afraid you must have calculated my bill wrong.
B: There is a possibility. I'll check it.
　　　　　　　　 　　　　　　　　 　　
A：服务员，恐怕你把我的帐单弄错了。
B：有这个可能。我去查一下。