下列短文的划线部分是错误的，请将其正确答案书写在后面横线上。

Nowadays people use the phone to talk with other almost anywhere on the world. But when you use the phone, you can't see the person you are talk with. This may change in the near future. Today some people are using a kinds of telephone called the picture Phone or videophone(可视电话).  With it, two people who is talking can see each other. Picture phones are useful if you want to show something to a person you're calling. They may have other uses in the future. One day you may be able to ring for a library and ask read a book. You'll be able to read the book right over your picture phone. Or you may be able to do some shoping through your picture phone. If you want to buy something, you can calling the shop. People at the shop will show you the thing right over the phone. You'll be able to shop all over the world and you needn't leave your room.

关于机组氧气系统组成说法正确的是（）

A、由一个固定压力的高压氧气瓶构成

B、由一个高压的便携式氧气瓶构成

C、由一个固定式氧气瓶、若干个氧气面罩以及一个PBE构成