Please help me on this

1. Open the door - Active Voice

Let the door be opened - Passive Voice

2. Prepare yourself for the worst. - Active Voice

Be prepared for the worst. - Passive Voice (correct?)

Both are imperatives, but why cant the second one be started with "Let" ?

Thanks in Advance
anonymousWe must endure what we cannot cure (active)

What cannot be cured must be endured. (passive)

Well grammatically, I don't see why not..."Let them be prepared for the worst" isn't incorrect. It is just questionable where this would be used....and that makes it sound odd...who is the person/entity who can decide whether or not they may be prepared for the worst?...who are they....?
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Dear Doha0011,

"Let's" is the imperative form of "we" and can't be used in your examples 'cause your sentence is an imperative form of "you".




Plz help me on this

We must endure what we cannot cure (active)

 Mister Micawber's reply was promoted to an answer.
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You must endure what cannot cure.