Changes the sentences into passive

EXERCISES 4:Changes the sentences into passive voice

23.Will buses bring the children home?
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24.Have you finished your homework?
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25.Must we finish the test before ten?
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26.Why didn’t they help him?
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27.How can they open this safe?
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28.How did the police find the lost man?
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29.How long have they waited for the doctor?
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30.How many marks does the teacher give you?
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31.Who lend you this book?
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