Below is an instruction that describes a task. Write a response that appropriately completes the request in Chinese. Please answer in Chinese.

### Instruction:
 在一个16 GB（千兆字节）容量的USB闪存驱动器上，已经使用了50%的空间。计算剩余可用的千兆字节数。


### Response:
 16 * 50% = 0.5 * 16 = <<16*50*.01=8>>8 GB的空间已经被占用。
所以，这个闪存驱动器上还有16 - 8 = <<16-8=8>>8 GB可用。