Подчеркните модальные глаголы либо их эквиваленты. Предложения переведите: 1. I cannot

Подчеркните модальные глаголы либо их эквиваленты. Предложения переведите: 1. I cannot understand how he managed to persuade his friend. 2. He will never be able to hear the serenade without a strange mixture of laughter and pain. 3. We think you must improve the situation. 4. She had to suffer a lot during the war. 5. You are to make a great effort of will to give up smoking.