Question

Task 4 Complete the definitions (1-8) below with words in the text.
1. An __________ is something medical put inside the body, e.g. a heart valve.
2. You need a good __________ to think of new and interesting ideas.
3. The __________ is the first or earliest.
4. ___________ are materials made from mixing two metals.
5. To ___________ means to become bigger.
6. To ___________ is to change because something else happens.
7. The __________ is everything around a person or thing.
8. To be __________ means to be made smaller.
Smart materials

Smart – or shape memory – materials are an invention that has changed the world of engineering. There are two types: metal alloys and plastic polymers. The metal alloys were made first and they are usually an expensive mixture of titanium and nickel.
Shape memory materials are called ‘smart’ because they react to changes in their environment, for example:
 plastics that return to their original shape when the temperature changes. One use is in surgery where plastics threads ‘remember’ the shape of a knot, react to the patient’s body temperature and make themselves into stitches.
 Metal alloys that have a ‘memory’ and can return to their original shape. They are used in medical implants that are compressed so they can be put inside the patient’s body through a small cut. The implant then expands back to its original shape. More everyday uses are for flexible spectacle frames and teeth braces.
 Solids that darken in sunlight, like the lenses in some sunglasses.
 Liquid crystals that change shape and colour. These have been used in climbing ropes that change colour if there is too much strain and weight on them.
The future of these materials and their possible uses is limited only by human imagination. One clever idea is that if cars were made of smart metal, a minor accident could be repaired by leaving the car in the sun!

Answer 1

Răspuns:

1. Metal alloy

2. shape memory/ imagination

3.The metal alloys

4.the metal alloys

5.expand

6.react

7. environment

8.compressed