One day, a man 1) (see) saw a boy across the street. The boy 2) (be) was very small and he 3) (can/not) ... reach the doorbell. The man 4) (walk) ... across and 5) (stand) ... next to the boy. "Don't worry," the man 6) (say) ... "I can help you." He 7) (press) ... the doorbell. "Now, what?" the man 8) (ask).... The boy 9) (answer) ... , "Now, we run!"

Решение:

1. One day, a man 1) (see) saw a boy across the street. (Прошедшее время, глагол 'to see').
2. The boy 2) (be) was very small and he (Прошедшее время, подлежащее 'boy' - ед. число).
3. 3) (can/not) cannot reach the doorbell. (Модальный глагол 'can' + отрицание 'not' сливаются в одно слово 'cannot').
4. The man 4) (walk) walked across and (Прошедшее время, глагол 'to walk').
5. 5) (stand) stood next to the boy. (Прошедшее время, глагол 'to stand').
6. "Don't worry," the man 6) (say) said ... "I can help you." (Прошедшее время, глагол 'to say').
7. He 7) (press) pressed ... the doorbell. (Прошедшее время, глагол 'to press').
8. "Now, what?" the man 8) (ask) asked.... (Прошедшее время, глагол 'to ask').
9. The boy 9) (answer) answered ... , "Now, we run!" (Прошедшее время, глагол 'to answer').

Ответ: 1) saw, 2) was, 3) cannot, 4) walked, 5) stood, 6) said, 7) pressed, 8) asked, 9) answered.