They have done all they could "to help" him.为什么是"to help"?

they couldn't have done better是什么意思 英语翻译I'm not sure what others would have done had they known that they wouldn't be here for the tomorrow that we all take for granted. They won't leave until all that can be done is done They have done all they could to help him.为什么是to help? can’t +have done All-----they have done is good for us A What B which C why D / All ( )they have done is good for me .填that 还是what i am__to my parents for all that they have done for me应该填哪个单词 They must have done their homework yesterday,___?为什么是didn't they?我觉得应该是haven't they啊? should have done ,shouldn't have done.could have done,couldn't have done They have done all __ stop the sisease from getting around.A.what they can B.they can to C.that they can D.what they can to lt was all my fault lshouldn’t have done that翻译中文 区别shouldn't have done 和 needn't have done musn't have done can't have done用法区别 they don't have a name 'cause they all have their own bands as well want them to ,doesn't mean they don‘t love you with all they have . Don't c about your parents.They have done their best. 1.Children couldn't have done all this damage.2.All of us will see him off at the airport.