It is useless to do?doing?

It is useless to do?doing? It is useless doing 或to do 有什么区别 it is no useless to do=it is no use doing but it is useless to do this now that you have become a prisoner 中文意思 i found it useless doing还是to do It's useless后面是doing还是to do? I think it's useless ___ when we have made mistakes.All we can do is to correct themA complaining B complained C having complained D being complained It is useless to c___,don't talk about it any more , (1/2)____that the train is gone,it is useless to wait. A Seen B see it is useless 后跟动名词还是不定式 whatever ,it is useless 的翻译 it is useless后面加什么? It is useless to worry about the things that had already happened.如何翻译? it is adj + doing or to do?会的请帮解答Q1.It is useful/useless/nice/good/interesting/expensive (to do / doing?)这种的it is 加 adj 後面的到底用哪种正确?似乎网上也很多人搞不太清楚有些说只能用 to do sth有些说只 Don,t want to lose you.My heart is so sad.It is useless.Really very painful! it is polite to do I'm wrong.I'm penitent heartfelt what about maybe it is useless so,what do i do 帮我翻译成汉语 think 是不是及物动词,那么句子''I think it is useless''中''it is useless'' 充当什么成分谢谢了,