The electric telegraph was invented. найдите и обозначьте страдательный залог, за хороший ответ 50 .

The electric telegraph was invented - Электрический телеграф был изобретён.
Was invented - это страдательный залог или по-другому пассивный залог. Используется, когда не важно, кто выполнял действие, важен результат. 

В этом предложении "was invented" является страдательным залогом(но его еще называют "пассивным залогом",это одно и то же).
У ЛЮБОГО предложения с страдательным залогом в нем есть одна общая форма. Это глагол to be+ глагол в 3 колонке(или добавляем окончание ed,как это тут,если глагол "правильный")
Был изобретен электрический телеграф-перевод предложения. В страдательном залоге ВСЕГДА действие происходит над подлежащим(над предметом).
Ну,так и все. Если еще останутся вопросы,но спроси потом в комментариях.

1 Last year I went to Paris and Rome. I liked both cities very much.

2 There were two pictures on the wall. I didn't like either of them.

3 It was a good football match. Both teams played well.

4 It wasn't a good football match. Neither team played well.

5 'Is your friend English or American? Neither. She's Australian.

6 We went away for two days, but the weather wasn't good. It rained both days.

7 A: I bought two newspapers. Which one do you want?

B: Either. It doesn't matter which one.

8 I invited Donna and Mike to the party, but neither of them came.

9 'Do you go to work by car or by bus? Neither. I always walk.

10 'Which jacket do you prefer, this one or that one?' 'I don't like either of them.

11 'Do you work or are you a student?' 'Both. I work and I'm a student too.'

12 Paula and I didn't know the time because neither of us had a watch.

13 Helen has got two sisters and a brother. Both sisters are married.

14 Helen has got two sisters and a brother. I've met her brother, but I haven't met either of her sisters.

Объяснение:

The flowers died because none of them watered.

2.Lunch was not prepared before we arrived.

3. We could not get on the plane because we left our passports at home.

4. The light was off because they forgot to pay for the electricity.

5. We were hungry because someone ate all the sandwiches.

6. The storm damaged the hotel, which was built a year ago.

7. The waitress brought in a salo, which no one ordered.

8. The cat was sleepy after being fed.

9. The windows were so dirty because they had not been washed.

10. I could not use my phone, it

Объяснение: