Answer:4, 5 

1 is incorrect because travel is only mentioned in the example of recovering from jet-lag. 2 is incorrect because countryside is only mentioned in the context of urban change. 3 is incorrect because time zones are only mentioned in the example of recovering from jet-lag. 6 is incorrect because although changes in government are mentioned, they are not mentioned as a difficulty. 4 is correct because the speaker says: It is in the smaller, everyday things that you might experience what is known as culture shock, although it's not really a shock, but puzzling all the same. For example, the precise way to behave at a supermarket checkout may have changed. 5 is correct because the speaker says: And in ordinary conversation, the frames of reference have changed, and quite often you find that you don't really know what people are talking about, even though they are speaking your native tongue.