Optimise B2 Unit 3 p. 27

when you suddenly have a great idea, or find the answer to a problem

changes from one system to another or makes something do it

hanging or swinging without anything stopping it

too big to be carried or stored

to obtain a special document that gives you the right to make or sell a new invention or product that no one else is allowed to copy

an extremely unpleasant experience, especially one that lasts for a long time

making small changes to something in order to make it as good or as effective as possible

using new methods, or achieving new results

an accident in which a person that is moving crashes into something