The given sentence is in a passive voice form, hence we need to convert it into an active voice form.
We need to follow these instructions while changing the voice of an interrogative sentence.
The inverted form of the verb i.e. Did you leave, will commence the sentence.
The given sentence is in the simple past tense.
The active voice form for the simple past interrogative sentence:
Helping verb (Did) + subject + V1 + object? At last line up the remaining part.
Following these steps, we finally get- Did you leave your bag in the bus?

The given sentence is in the active voice. We have to change the sentence into passive form.
The given sentence is written in 'present perfect tense.'
The structure of these kinds of sentences is:
Active Voice: Subject + have/has + V3 + Object.
Passive Voice: Object + have/has + been + V3 + by (preposition) + Subject.
Let’s see another example:
Active voice: I have written this instruction only for visitors.
Passive voice: This instruction has been written by me only for visitors.
The subject of the given sentence is 'Shalu' and the object of the given sentence is 'new copies of the album.'
So, in the passive voice, the position of ‘subject’ and ‘object’ will be interchanged.
Also here, 'has ordered' will be changed into 'have been ordered'.
Correct Sentence: New copies of the album have been ordered by Shalu.

The past continuous tense is employed to create the passive sentence.

The given sentence is in Passive Voice. As per the question we have to change it into Active Voice.
The structure of the given sentence as follows: Subject+has/have+V3+Object.
(Active Voice) Subject (Objective Case)+has/have+been+V3+Object (Subjective Case).
(Passive Voice) 'The plan' will be put in place of 'we'.
(Subject becomes object) And 'We' will be put in place of 'The plan'.
(the object becomes subject) 'Have looked at' will be changed into 'Has looked at'.
(To agree with the changed subject and object) Thus the correct sentence is:
The plan has been carefully looked at