We know that Pythagoras discovered this theorem.

It is known that...

We know that Pythagoras discovered this theorem.

Pythagoras is known...

Many people consider Bob Dylan to be the most influential musician of the twentieth century.

Bob Dylan ...

Experts believe that 1.24 million people were killed in road traffic accidents in 2010.

Road traffic accidents ...

Palaeontologists think there were over 500 different species of dinosaur.

There are thought ....

We know that cats are able to produce about ninety different sounds more than dogs.

Cats ...

The Arabic numeral system _____ in India.

• is thought to have evolved

• is thought to evolve

Ancient Egyptians are considered _____ to the development of mathematics

• to contribute

• to have contributed

You are _____ for your exams in the summer.

• expecting to have studied

• expected to be studying

They weren’t _____ in this case.

• thought to be involved

• thinking to have been involved