4 While he ___________(travel) on the bus to work, he ___________(remember) that it was his wife's birthday.

4 While he was traveling on the bus to work, he remembered that it was his wife's birthday.

Перевод: Пока он ехал в автобусе на работу, он вспомнил, что сегодня день рождения его жены.

Ответ: While he was traveling on the bus to work, he remembered that it was his wife's birthday.