Say it in the passive C1

Laughing 100 times is considered to use the same energy as fi ft een minutes cycling.

It is widely agreed that most medicines will be printed by 3-D printers in the future.

It is said that by 2020, the number of people aged 60 years and older will outnumber children younger than fi ve years.

It is believed that our life expectancy has increased more in the last fi ft y years than in the entire human existence.

Hippocrates of ancient Greece is widely agreed to be the father of western medicine.

It has been suggested that people who run regularly live on average six years longer.

It’s believed that two-thirds of all the people in the world who have ever lived to be 65 years old are still alive today.

Penicillin is considered to have been discovered by Alexander Fleming.

The pace of population ageing is believed to be much faster now than in the past.

In fifty years’ time, it is expected that the jobs of nurses and carers will have been taken over by robots.

It has been calculated that a third of humans’ lives are spent sleeping.

It is said that life expectancy in ancient Rome was 20–30 years.

Humans are understood to have become 50% heavier in the past 100 years than they have been throughout history.

It has been determined that there are more living things living on your skin than people on the planet.

The average person is considered to walk the equivalent of four times around the world during his/her lifetime.

People are known to be able to survive for two months without eating, but only eleven days without sleeping.

It is proposed that women live longer than men partly because their immune systems age more slowly.

It is widely agreed that countries have to start making provision to look aft er their ageing populations.