Why he (to cross) the street without his parents now?

Решение:

В этом предложении используется Present Continuous, поэтому глагол 'cross' должен стоять в форме Present Participle.

1. Начальная форма глагола: cross
2. Форма Present Participle: crossing

Ответ: Why he (to cross) the street without his parents now? → Why he crossing the street without his parents now?