Перечислить периуд палиозойской эры

Делится на 6 периодов: кембрий, ордовик, силур, девон, карбон и пермь. В начале эры южные материки были объединены в единый суперконтинент Гондвану, а к её концу к нему присоединились другие континенты и образовался суперконтинент Пангея.

2 They would have arrived on time if the train hadn't broken down. (arrive)

3 If he hadn’t forgotten his keys, he wouldn't have gone back home. (not forget)

4 You would have seen my message if you had checked your mobile phone. (check)

5 I would have missed the flight if the plane hadn't been delayed. (miss)

6 If you'd concentrated on what you were doing, you wouldn’t have made so many mistakes. (not make)

7 If I'd known it was going to snow, I would have worn a coat. (wear)

8 We wouldn’t have invited Joe if we'd known you didn't like him. (not invite)

Объяснение:

3 Conditional = if+Past Perfect—> would+ have+V3