We must be kind to the old.为什么be kind to这个词组在句中不可以写成We must are kind to the old.

将下列英语句子转换成祈使句YOU MUST BE KIND TO HIMYOU MUST'T EAT LUNCH NOWSHOW WE PIAY TENN'T AFTER SCHOOL? We must be kind to the old.为什么be kind to这个词组在句中不可以写成We must are kind to the old. Finally,teenagers must not be selfish.We should be kind to others_______.空里填什么吗?Finally,teenagers must not be selfish.We should be kind to others_______.空里填什么（it hard instead especial be） 可以变型 we must be kind poor and old people.可选A.of B.to C.in D.for Don't be( )(kind) to animals. We must be l------- to the school we should be kind to animals .we should ___ ___animals they must promise --- their new pets.A kind to B being kind to C to be kind of D to be kind to we ---to succeed this time ,we won't be given another chance.---应该填ought,还是must must be a kind girl Nobody likes ,so we should be kind to eNobody likes ,so we should be kind to everyone. We learn to be ___kind______ (kind) to animals.请问,横线上为什么要填kind呀? something must be done something must be done to ＿＿＿＿（stop) this kind of thing _______(happen) You must be confident and proud in this kind of T shirt.[翻译成中文} knowing is't enough be wonder we must apply be must apply wound is't enough who is next we must doknowing is not enough be wonderwe must apply be must applywound is not enough who is nextwe must do We must try our best to be green _______.(consume) We must try our best to be green _______.(consume) We must be able to flee the city