It contains daily news ( active) (Passive) Daily news is contained in it Why we use is (in ) in the passive form?why not we use by in there?

In passive voice, the preposition "by" is used to indicate the doer of the action, while "in" is used to indicate the object of the action. In the sentence "Daily news is contained in it," the focus is on the fact that daily news is contained within the object (it), rather than who is doing the containing. Therefore, "in" is used to show the location of the daily news within the object.

In the passive voice, the object of the active voice becomes the subject, and the subject of the active voice becomes the object of the preposition "by." In this case, "daily news" is the object of the active voice, so it becomes the subject of the passive voice. "It" is used as a placeholder subject in the passive voice, so we cannot use "by" here.

Therefore, the correct passive voice is:

Daily news is contained in it.