Ответ:

1 They believe the famous singer is in town.

a The famous singer is believed to be in town.

b It is believed that the famous singer is in town.

2 They say the new X-Men film was a hit.

a The new X-Men film is said to have been a hit.

b It is said that the new X-Men film was a hit.

3 Locals think the art gallery is closing down.

a The art gallery is thought to be closing down.

b It is thought that the art gallery is closing down.

4 People believe that the writer has created an excellent plot.

a The writer is believed to have created an excellent plot.

b It is believed that the writer has created an excellent plot.

5 They say that the sculptures are so lifelike.

a The sculptures are said to be so lifelike.

b It is said that the sculptures are so lifelike.

Объяснение:

Когда нам надо передать чьи-либо высказывания или предположения о ком-либо или о чем-либо, мы можем употреблять два типа конструкций с глаголом-сказуемым в страдательном/пассивном залоге.

1) It + passive (is believed/said) + that + придаточное предложение.

2) Subject + passive + to infinitive.

Инфинитив может иметь различные формы. Например, если речь идет о действии, совершившемся ранее, употребляется конструкция to have + past participle.

Обороты it + passive соответствуют в русском языке глаголам с неопределенно-личным значением. Наиболее часто встречаются:

it is said - говорят; it was said - говорили;

it is reported - сообщают; it was reported - сообщали;

it is expected - ожидается, ожидают; was expected - ожидали;

it is believed - полагают