How to make friends with British girls?

I am a Chinese guy,who is studying abroad here for 6 months so far.
But I have not had any British friends. There are some British flatemates in my flat,but i think it is hard to make friends with them, first, they speek too fast, my english is poor,so i can not catch up with them. second, they are indifferent. third, i do not know what i should say for talking. And i do not have more chance to access more British people,in my class,few british,in my flat,few british, that's all. I know there are lots of british in the campus, but i can't go to talk with them directly on the street, it is weird.
I am very frustrated now.

hey, I think a lot of British people are a bit intimidated by Chinese people, and think that they don't really want to mix. All you can do is make a real effort to spend time with them and chat to them, explain they might need to speak a bit slower and you are keen to practice your English. I think most people would be quite welcoming, don't be shy!

Use the universal language of math!

Thanks! But i am worried about they are not patient to do that.

I think your poor English (in particular, your listening skills) is probably going to be your biggest problem. But, the only way to deal with that is the practice! So, try and talk to them, ask them to slow down a bit when you need them to, and just listen to the conversation when you're a part of a group - even if you struggle to understand everything they say and so struggle to respond, just listening and trying to understand will help you. Does your university also have an English language support centre? If so, make use of it! It will help you with both your studies and your social life.

What you perceive as indifference is probably just the British being British. We can tend to be a bit more reserved than people from some other countries, such as the Americans. It's not that we don't care about things, we just show it in a different way. Alternatively, what you're finding out is that the Chinese have a massive reputation for not wanting to socialise with the British students. They see you as not making an effort, and so they assume that you fit into that stereotype, and so they don't bother with you. You've got to make an effort to socialise with them and break that stereotype.

In terms of what to talk about, start with what we call 'small talk'. The British are famous for talking about the weather all the time, and that is one example of small talk. Other examples are asking them how their day was, sports, topics in the news, music etc. From there onwards, you can move onto more substantive topics.

The British have a great tendency to use alcohol when we're socialising, and one big reason for that is that it gets you past the awkwardness as it's pretty difficult to feel awkward when you're a bit drunk! Next time your flatmates are going out, even if it's just to the pub, go out with them too.

I know you say you're having trouble meeting British people, and you're right that just randomly talking to people in the street is likely to be seen as a bit weird. Probably your best bet is to join a society. You don't say which uni you're at, but there's normally a big variety at every uni, and your students' union will have a list of everything on offer. They're a really good way to meet people, because when you have a shared interest and something you can do together (e.g. playing football) you've got something in common already and it's not just all about talking.