In the past it was thought that swimming in the sea was bad for you.
In the past it was thought that swimming in the sea was bad for you / In the past swimming in the sea was thought to be bad for you.
People know that she is a good swimmer.
She is known to be a good swimmer. / It is known that she is a good swimmer.
They said Francis was in hospital last week.
Francis is said to have been in hospital last week.
People believe that the robber had been working in the bank.
It is believed that the robber had been working in the bank. / The robber is believed to have been working in the bank.
People believe that nuclear power stations cause damage to the environment.
It is believed thar nuclear power stations cause damage to the environment. / Nuclear power stations are believed to cause damage to the environment.
