Братишки ! помогите с Инглишем 2 задания перевести! только по правилу pefect infinitive! только без переводчиков!

He could have drowned but his brother saved him.
She could have won in the championship but luck was against her. 
You might have called! why didn't you ? we were worried 
Borodin might have been a good chemist but he became a famous composer.