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Нельзя, it's an order in the future tense, as it seems to me
I can be wrong about the reason, just my intuiton :)

Don't stare- не смотри (не пялься is possible too :), but it's not polite at all)
Chew with your mouth closed- жуй с закрытым ртом

Двухлетняя девочка упала с стула и *cut her head* поранила голову