"It's a time of high stress and if they are surrounded by noisy siblings who have music blasting out or are playing noisy video games it can be hard to concentrate and feel like every one else is enjoying themselves, " she says.

BBC: Tips on how to survive the exam season

Nevertheless, it may still be hard to persuade Mr Magalhaes to concentrate on economic reforms rather than on an inquiry he has instigated into corruption among judges, which, together with another into the banking system, has occupied much of the Senate's time so far this year.

ECONOMIST: Cardoso��s reform puzzle

Readers who did not spend the last 20 years following the twists and turns of Polish politics will need to concentrate hard to grasp who knifed whom, when and why.

ECONOMIST: Poland's modern history

Partly because it is so hard to grasp what these numbers mean, recent historians have tended to concentrate on particular theatres or aspects of the war with an emphasis on trying to describe what it was like for the human beings caught up in it.

ECONOMIST: The second world war

Chinese tourists are willing to put up with hard beds and cold noodles for a reason: they are champion shoppers who prefer to concentrate their spending on luxury branded goods, which are cheaper than back home and guaranteed not to be fakes.

ECONOMIST: Chinese tourism

Newspapers have already been hit hard by the recession and decisions by some advertisers to concentrate online.

BBC: Debate on the Scottish newspaper industry

He said the pupils should concentrate on hard work, getting good skills and an education to make them attractive to potential employers.

BBC: Crunch questions for top politicians

But the appeal of letting the Americans get on with what they know best, freeing himself to concentrate on the French stuff, while taking a stake in any new entity, might be hard to refuse.

ECONOMIST: Vivendi Universal

Worcestershire is one of the areas where the BNP has decided to concentrate its efforts, so attention will inevitably focus on towns like Redditch and Bromsgrove that have been hard hit by job losses during the recession, especially in manufacturing industries.

BBC: BNP to target recession hit towns