Work in small groups. Choose one of the metals mentioned in the text. Think of seven interesting ways it could be used nowadays. Compare your ideas with other groups.
13. What do you think will happen when the world runs out of metals? Write a short paragraph (60 - 80 words) to answer this question.Use the phrases in the box:
First of all lets try to analyse In my opinion,
Another negative aspect of Its also true that
I can (cant) agree that To sum up,
GRAMMAR IN USE
These tasks can help you to practise The Present Simple Passive (See Appendix 1 p. 228 230) and do the following exercises.
Complete the sentences, as in the example.
e.g. 0. It is thought that the college has good teachers.
The college is thought to have good teachers.
1. It is known that people use metals.
2. It is reported that our students work hard.
Our students .....
3, It is said that she speaks seven languages.
4. It is said that he is a talented scientist.
5. It is said that our university team trains for eight hours every day.
Our university team
6. It is reported that the world leaders discuss different problems.
The world leaders
7. It is thought that she drives a car.
She is thought .
Put the verbs in brackets into the Present Simple Passive.
1. The post .. (to deliver) at about 7 oclock every morning.
2. The rubbish .. (to take) away three times a week.
3. The name of the person who committed the crime .. (not / to know).
4. The building .. (not / to use) anymore.
5. These computers .. (to make) in Taiwan.
6. Coffee ..... (not / to grow) in Europe.
7. The Statue of Liberty .. (to locate) on Liberty Island, in New York.
16. Transform sentences from the Active into Passive Voice.
1. People develop different methods.
2. Metals can conduct heat and electricity.
3. They can draw an ounce of gold into a wire.
4. People use bronze for objects intended to resist the corrosive action of the atmosphere.
5. You can bend elastic materials.
6. People know zinc as one of the constituents of the alloy brass.
7. We call bronze an important material in the scientific and technical progress.
In the following description of how plastics are shaped, put the verbs in brackets into the Present Simple Passive.
There are many ways of shaping plastics. The most common way is by moulding. Blow-molding (a) .. (to use) to make bottles. In this process, air (b) .. (to blow) into a blob of molten plastic inside a hollow mould and the plastic (c) .. (to force) against the sides of the mould.
Toys and bowls (d) .. (to make) by injection moulding. Thermoplastic chips (e) .. first .. (to heat) until they melt and then forced into a water-cooled mould under pressure. This method (f) .. (to suit) to mass production. Thermoplastics can (g) .. (to shape) by extrusion. Molten plastic (h) .. (to force) through a shaped hole or die. Fibres for textiles and sheet plastic may (i) .. (to make) by extrusion.
1. Look at the objects in the pictures. What materials do you think they are made of and why?
2. In pairs, discuss what is meant by mechanical properties. What mechanical properties do you know?