The new discussion focuses on a class of substances called promoters.

These contained a substance called Spread, and, indeed, that was all you could do with it.

Also some substances, called stimulants - coffee is such an example - can cause poor sleep.

The rest is formed from an invisible substance called "dark matter".

One thing that builds up is a substance called bilirubin.

The main difference between other series is the use of a substance called Regel.

Together we've tasted a tiny piece of the sweet substance called hope.

The letter to Collins said there was evidence she used a substance called "the clear."

They protect the body from damage by substances called free radicals.

According to the theory, the body was filled with four different substances, called humours.