这个问题并不正确，how long并不能决定后面句子的语态。在how long后面接主动语态和被动语态都可以。
如：How long did you do the work? 这份工作你做了多少时间这是主动语态，改成被动语态可以是How long was the work done?
所以how long后面接主动语态和被动语态都可以。
后面多用一般现在时和一般过去时，如：Long does it take to get to school
How long did it take you to get here?
