A bus conductor checks passengers' tickets and collects money on a bus.

Could you ask her to call me back?

A decade is a period of ten years.

Traditional African culture puts an emphasis on oral story telling.

His phone is engaged – he must be talking to someone.

Entrepreneurs in Ghana charge people to make calls from phone towers.

I went on speaking but he couldn't hear me.

The use of mobile phones in Africa has gone up dramatically.

Hold on, I'll put you through.

What time does the football match kick off?

Africa is the first continent to have more mobile phone users than landline users.

Oh, sorry, the line's engaged.

People with mobiles no longer have to walk miles to make a deal.

Phone use is a means of social and family contact.

It's estimated that phone ownership was nearly 100% by the time of the World Cup.

I'll pass your message on as soon as possible.

You can't pick up a signal on your mobile in a tunnel.

Hold on, I'll put you through.

They plan to put up a mobile phone mast near our school.

Africa's mobile phone revolution is likely to go on for many years.

People died because they couldn't ring up a doctor.

Phone use is a means of social and family contact.

A sociologist is someone who studies societies and the way they are organized.

The pace of life in Africa is speeding up.

A street vendor sells things in the street, for example, clothes or food.

Africa is the first continent to have more mobile phone users than landline subscribers.

Mobile phone subscriptions went up from 54 million to almost 350 million.

ITU stands for International Telecommunications Union.

If you climb to the top of the tall towers you can pick up a mobile phone signal.

Mobile phones are used to transfer money.

The mobile phone explosion is transforming Africa.

Africa has more mobile phone users than Europe.