The impersonal passive construction with the infinitive

Complete the second sentence so that the meaning stays the same:

People think that thousands of caves exist in China.

Thousands of caves ___ in China.

Complete the second sentence so that the meaning stays the same:

We know that many people have died on such expeditions.

Many people ___ on such expeditions.

Complete the second sentence so that the meaning stays the same:

People believe that the ice in Antarctica is disappearing.

The ice in Antarctica ___.

Complete the second sentence so that the meaning stays the same:

We know that the Sahara Desert contained water only 5,000 years ago.

The Sahara Desert ___ water only 5,000 years ago.

Complete the second sentence so that the meaning stays the same:

Experts believe that some deep-sea creatures have existed for millions of years.

Some deep-sea creatures ___ for millions of years.

Complete the second sentence so that the meaning stays the same:

People said that the cave was 500 metres deep.

The cave ___ 500 metres deep.

Complete the second sentence so that the meaning stays the same:

People felt that the project was too expensive.

The project ___ too expensive.

Complete the second sentence so that the meaning stays the same:

Experts said that the tax changes helped poorer people.

The tax changes ___ poorer people.

Complete the second sentence so that the meaning stays the same:

Many people say that a fight between rival fans broke out after the match.

A fight between rival fans ___ after the match.

Complete the second sentence so that the meaning stays the same:

Everyone considered that his behaviour had been unacceptable.

His behaviour ___ unacceptable.