i found it useless doing还是to do

i found it useless doing还是to do ()I'm_________music.How about you?---I'm not good at it A.good B.good at C.useless D.well I am useless at it I am good at itI am useless at it I am good at it 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, 单选题：We found it useless ( ) to persuade him to go with us.A:try B:trying C:to try D:triedPlease tell me which option should be chosen And why? 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 I found （ ）hard to learn to swim.A it B I C he D you 什么时候是I found it 什么时候是I found that The old man looked at him straight in the eyes and said,“I looked into their eyes,I found they didn’t care,__7__ told me it would be useless,but when I looked into __8__,I saw kindness.”为什么7填which为什么8填yours I found _____easy to learn English well.a)this b)it c)that d)its I found ___hard to speak English in ciass.A.that B.it C.how D.what I found it ( ) class two,grade seven A.in B.to C.of D.at I found it _____ hard work.A an B a C the D / I found it _hard work A.a B.an C.the D./ I found it hard___(learn)English well 比如:I found it interestingEatingThere .(理由) I found it hard to living. i found it important to stard hard