... practice bullying(-)
Don't practice bullying!
(+)
Stand up!
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Clean your bedroom!
(-)
Don't play video games in the classroom!
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Wash your hands!
(-)
Don't sleep in class!
(-)
Don't use your cellphone!
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Don't talk in the library!
(-)
Don't sit down!
...,read a book(+)
Plese, read a book!
(+)
Do your homework!
(-)
Don't run!
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Help your friend!
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Go away!
... your teacher(+)
Respec your teacher!