Put what you have done to show you are eager to work. Start with the recent relevant bits so they get read. Push anything you think may be relevant to the job you are going for. Simple mentions for the rest to show you were actually doing something. Consider what you do in your spare time, there may be evidence of the sort of go-ahead individual you would be best projecting. I think at your age there is little reason to leave much out, that comes when you can put so much you need to work out what will be considered useful and what simply tedious to read. Why not put in about studying abroad ? It's better than doing nothing during that period. Be precise and clear about what you studied, why & how. But not too long winded, just enough to pique interest. Where you put it will depend on your CV style. If you separate work from study, then in the relevant paragraph. If you put it together in importance/date order, again in the right date/importance slot.