Earth's core

It seems we now know more about outer space than we do about the Earth's core. This is because temperatures are so [high:broad] at the centre of the Earth that human beings have not been able to take a close look at it. However, new [methods:processes] of analysis may soon change all that. The seismic waves [created:harmed] by earthquakes and volcanic eruptions penetrate the Earth's layers at different speeds. It is now hoped that by studying these waves, scientists will be able to make new [discoveries:inventions] and solve some of the mysteries of the [internal:central] structure of the Earth.