Don't be cruel to animals.
動物愛護を
Don't be crushed by it.
そんなことで弱音をはくな
Don't be discouraged.=Don't let it discourage you.
がっかりするな
Don't be familiar with me.
なれなれしくしないで
Don't be foolish!
ばかなことをするな[言うな]
Don't be frightened to speak up.
臆せず発言してください
Don't be funny.
おちゃらかすな;もっとまじめにやれ
Don't be impatient with the children.
子どもに短気を起こしてはいけない
Don't be late or you'll be left behind.
急がないと置いて行かれるぞ
Don't be long.
ぐずぐずするな