Задание №81568 ЕГЭ Английскому языку

Преобразуйте, если это необходимо, слово « NOT CAN» так, чтобы оно грамматически соответствовало содержанию текста.

Fred went blank. He thought and thought but ______________ remember. Then a smile broke across his face and he asked, "What do you call that flower with thorns?" "You mean a rose?" "Yes, that's it!" Then he turned to his wife and asked, "Rose, what was the name of that clinic?"