Iran's leader, Ayatollah Ali Khamenei, has been killed in an attack by the US and Israel. Find out the background to Iran and its relationships with the United States and Israel.

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Random numbers are very important to us in this computer age, being used for all sorts of security and cryptographic tasks. [Theory to Thing] recently built a device to generate random numbers ...

If you love learning about the body, then you'll be pleased to hear Dr Chris and Dr Xand are back on CBBC for a new series of ...