改成一般现在时He enters his office
His office is entered by him .
现在进行时 He is entering his office .
His office is being entered by him .
一般将来时 He will enter his office
His office will be entered by him
一般过去式He entered his office
His office was entered by him
现在完成时 He has entered his office .
His office has been entered by him.
过去完成时He had enteed his office
His office had been entered by him
过去进行时 He was entering his office .
His office was being entered by him.
过去将来时 He would enter his office .
His office would be entered by him
加油!不明白再问!