5 July 2012 Last updated at 08:35

How to catch Olympics cheats

In just few weeks, the world's top athletes will come together for the biggest sporting event on Earth - the Olympics.

To make sure the competition is fair, competitors will be tested to make sure they haven't taken drugs to improve their performance.

One group of children won a competition to take a look at the science labs where the tests will be done.

Rosie and Megan took Newsround on an exclusive tour.

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Special section: London 2012 Olympics

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Pictures: Olympics closing ceremony

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Quiz: London 2012 Olympics

Try our London 2012 Olympic Games quiz with fun questions and answers for kids.

Quiz: London 2012 Olympic venues

Try our London 2012 Olympic venues quiz with fun questions and answers for kids. It's free!

London's very first Olympics

An exhibition looks back at the first London Olympics and what the Games looked like back in 1908.

London 2012, Olympic venues quiz

Things are shaping up for the Olympics. The athletes are on their way and and the venues are ready, but how much do you know about the places where the drama will take place?

1.) Question 1

How much water will the Aquatics Centre use?

5 million litres
30 million litres
10 million litres

2.) Question 2

What type of sport will this specially-built course at Lee Valley be used for?

Watersports
Triathlon
Cycling

3.) Question 3

Which event will take place here at Horse Guards Parade?

Beach volleyball
Watersports
Boxing

4.) Question 4

Which of these events will be held here at the O2 Arena in Greenwich?

Beach volleyball
Watersports
Gymnastics

5.) Question 5

Which event will be held here in this sweeping building?

Athletics
Track cycling
Fencing

6.) Question 6

Olympic football matches will be held at how many different stadia across the UK?

One
Three
Six

7.) Question 7

* Stadium will host the Olympic football finals.

Wembley
Millenium
Old Trafford

8.) Question 8

Outside London, * locations will host competitions.

9.) Question 9

Where in London will the Olympic tennis matches be played?

Queen's Club
Wimbledon
Stratford

10.) Question 10

Which of these events won't be held at a venue, but along the streets of London?

Triple Jump
Marathon
400m sprint

Answers

The Aquatics Centre is where swimming stars like Rebecca Adlington and divers like Tom Daley will compete. It will use at least 10 million litres of water.
This specially-built river at Lee Valley is for watersports like the canoe slalom.
Thousands of tonnes of sand have been shipped in to make a fake beach for the beach volleyball games. It's at Horse Guards Parade in London which is really close to Buckingham Palace.
This famous London landmark, known as the O2 Arena, is normally used for big music concerts - but during the Olympics gymnastics will be held here.
In this velodrome Olympic track cycling will take place. Gold medallist Sir Chris Hoy will come here to compete, along with other stars like Victoria Pendleton.
There are six football stadia across the country where the Olympic football matches will be played.
Wembley Stadium will host the Olympic football finals for the men's and women's competitions.
Even though London is the main city hosting the 2012 Olympics, ten venues outside the capital city will also host Olympic competitions during the summer.
The courts at Wimbledon will host the tennis matches for the Olympics, just weeks after the Wimbledon tennis tournament.
The marathon will be run through the streets of London. Other events taking place on London's roads will include cycling road races and the 50km walk.