4. Nick (play) the guitar while Kate (write) a letter.
Для решения данного задания необходимо знать формы глаголов в Past Simple и Past Continuous.
Ник играл на гитаре, пока Кейт писала письмо.
Правильные формы глаголов:
Получаем предложение:
Nick was playing the guitar while Kate was writing a letter.
Ответ: Nick was playing the guitar while Kate was writing a letter.