Kidneys. Test yourself
How many kidneys do you have? 1, 2 or 4?
What is a kidney like? A sieve, a pump or a bag?
What do the kidneys give back to the blood? Sugar, rubbish or sand?
What colour of wee says drink some water? Clear, dark or pale yellow?
Where are the kidneys? Near your back, in your head or in your legs?