Unit 7: DIFFICULT WORDS
Crane: a large machine with a long metal arm that is used for moving or lifting heavy objects.
Skyscraper: an aextremely tall building.
Titanium: a hard silver-grey metal that is combined with other metals to make strong, light materials that do not easily rust (=react with air over a period of time).
Aluminium: a light silver-coloured metal that is used for making cooking equipment, etc.
To pump: to force a gas or a liquid to go in a particular direction.
Sample: a number of people or things taken from a larger group and used in tests to provide information about the group.
Shape: an example of something that has a particular form.
To heat up: to become or to make something hot or warm.
To cool down: to lower the temperature of something.