floppy disk
软盘 

例句：
Floppy disks have always been cheap to make and relatively easy to copy.
软盘制作成本比较低，而且拷贝起来也相对容易些。
 

swim against the current (stream)
逆潮流行事；背道而驰
 
例句：
The boy who tries to succeed today without an education is swimming against the stream.
现在，没有受过教育的青年想要获得成功，其难度就好比逆水行舟。
 

I can't believe it.
我简直不敢相信。
　
对话：
A: She beat two world records.
B: That's amazing.
A: It sure is. I couldn't believe it.

A：她打破了两项世界记录。
B：那太令人惊奇了。
A：当然。我简直不敢相信。