how things work

The most important part of the object is a strip of two different metals, one on top of another. As they heat up, both metals expand, but one does it faster than the other. The strip bends and connects with a switch, which turns off the power supply. When the strip cools down, the metals contract and the switch is disconnected.

The object has several component parts, most of which are made of plastic. A disc inserted into the object spins quickly. At the same time a thin beam of light strikes the disc and converts digital symbols into sounds. The sounds can be increased and decreased in volume by means of a button or dial.

Liquid and gas are compressed in a hard metal tube. This can be released by pushing or squeezing a button which opens a valve. When the liquid-gas combination leaves the tube and is mixed with oxygen, it rapidly expands.

The object is mainly made of aluminium. As it moves forward, air flows over two horizontal sections. As it accelerates, a vacuum is formed over the horizontal sections and the object is pulled into the air by the force of this vacuum.

This object consists of two main parts: one is made mainly of plastic and metal, the other is made mainly of glass. Light enters the glass section and a small door in the device opens up when a button is pressed. At the same time,  smaller window called an aperture adjusts itself to control the amount of light. The light is then adsorbed and a sheet of plastic coated in a special chemical. An image is formed and this can then be processed and developed into a two-dimensional paper-based object.

A sharp blade inside a plastic container rotates very quickly. It chops or grinds anything it touches, which we can then use to produce soup, sauces and dressing.

This is a very simple object which originates from China. A small piece of paper is lit with a match. It burns away until the flame ignites the chemical compound inside a cardboard tube. The result is a display of light and colour.

describing & analysing tables

considerable discrepancy (or conflict)
- something not right.

sudden and noticeable difference

rise dramatically

increase slightly

go up sharply

sharp drop

remain constant

verb related with changes

we need to adapt these cars so disabled people can drive them. 

the country found it hard to adapt to the new government

To make sure your car is safe to drive, you should check and adjust the brakes on a regular basis.

He found it hard to adjust to a tropical country.

You must transform the voltage or the system will blow up.

He decided to transform his appearance by having plastic surgery.

Our bills will be less if we switch from gas to electricity.

They had to switch flights at Heathrow Airport.

You cannot alter the terms of the contract once it has been signed.

He wants to alter his appearance.

It will help your digestion if you vary your diet.

Prices of flats vary from a few thousands to millions of pounds.

We need to exchange our pounds for dollars.

You can usually exchange goods which are faulty if you show the receipt.

We have had to expand our sales force to cope with the extra demand.

Water will expand when it is frozen. 

The price of oil will increase next year.

Most bosses refuses to increase salaries when they are asked.

The management decide to dissolve the company and sell the offices.

Dissolve the sugar in boiling water.

More and more people are moving to cities to swell the population there.

The swap sting caused his leg to swell up.

The market for typewriters will probably disappear completely in the next few years.

The police are confused by the increasing number of people who disappear this year.

The old contract ran out and we had to renew it.

Many people argue that it's futile to renew old hostilities. 

They have received funds to renovate the old building.

The house is in good condition, but we need to renovate the central heating system.

The boss offered to promote him from salesman to manager.

Our main aim is to promote tourism in the country.

If you washed it too much, the colour will fade.

We watched the islands fade away into the distance. 

The company decided to replace the permanent staff with freelancers.

You must replace the books on the shelf when you have finished with them.

The doctors were unable to cure her illness.

Preserve the meat in salt water for between three and five days.

Governments are trying to reduce pollution. 

The best way to save money is to reduce the number of staff.

Conditional Statements

Part I:

You can borrow my dictionary providing that you return it before you go home.

You cannot go to university unless you have good grades.

Pollution will get worse as long as we continue to live in a throw away society.

Many developed countries are willing to waive the Third World Debt on condition that the money is invested in education and medicine.

Some countries will never be able to rectify their deficits no matter how hard they work.

Computers are difficult things to understand, however many books you read about them.

Crime is a problem, wherever country you go to.

Part II:

Providing that you can return it before you go home, you can borrow my dictionary.

Unless you have good grades, you cannot go to university.

As long as we continue to live in a throw away society, pollution will get worse.

On condition that the money is invested in education and medicine, many developed countries are willing to waive the Third World Debt.

No matter how hard they work, some countries will never be able to rectify their deficits.

However many books you read about them, computers are difficult to understand.

Wherever country you go to, crime is a problem.

Part III:

Being able to drive is one of the prerequisites of the job of salesman.

Before you accept a job, it is important that you agree with the conditions of the contract.

It is a requirement of the university that you attend an interview.