Преобразуйте данное предложение, используя все настоящие времена и делая необходимые изменения: they take part in exhibitions every year.

They take part in exhibitions every year. - Present Simple
They are taking part in exhibitions constantly. - Present Continuous
They have taken part in exhibitions this year as well. - Present Perfect
They have been taking part in exhibitions every year for 5 years . - Present Perfect Continuous

Socrates was Greek,

There weren't a lot of people in the supermarket.

Apollo wasn't born in Athens.

You were my best friend.

I was a strong baby.

There was a cat on the bed.

Запомните: Is, Is not — Was; Are, Are not — Were, Am — Was. Socrates is Greek. — В данном случае настоящее время определяется смысловым глаголом is (формой глагола to be). Для того, чтобы изменить время, необходимо изменить форму смыслового глагола на was: Socrates was Greek.There aren't a lot of people in the supermarket. — То же самое: смысловой глагол are (с отрицательной частицей not) является формой глагола to be для множественного числа. Меняем are на were(с частицей not): There weren't a lot of people in the supermarket. Apollo isn't born in Athens. — Isn't с частицей изменяем на wasn't (причём born не трогаем, это не глагол): Apollo wasn't born in Athens.You are my best friend. — are меняем на were: You were my best friend.I'm a strong baby. — Форма глагола to be, выраженная am, характера только для первого лица единственного числа, то есть I. Аналогично, am изменяется на was: I was a strong baby.There is a cat on the bed. — Смысловой глагол is меняем на was: There was a cat on the bed.

1) A: It takes him ten minutes to get to work.

B: I know. His house is far from the office.

2) A: Isn't your son an actor?

B: Yes, but at the moment he is working in a restaurant.

3) A: What is all that noise? I'm trying to work!

B: I am playing with the children.

4) A: What do you know about the new software program?

B: The new software program? Absolutely nothing.

5) A: Why are you wearing that jacket in the office? It's really warm!

B: Because l'm cold!

6) A: Would you like some beef?

B: No, thanks. I don't eat meat. I'm a vegetarian.

7) A: Why are you standing there?

B: I am waiting for a taxi.

В пятом не совсем уверен, можно ли там вставить are, грамматически все правильно, но вдруг формы be можно использовать всего один раз.