下列物质的顺反异构体是什么?
ch3ch2ch2ch=chch2ch3
ch3ch=chch2ch(ch3)2
ch3ch2ch=c(ch3)ch2ch3
ch3ch=c(ch3)ch(ch3)2
ch3ch2ch2ch2ch=chch3
ch3ch2ch=chch(ch3)2
ch3ch2ch2c(ch3)=chch3
ch3ch=chch(ch3)ch2ch3
ch3ch=chc(ch3)3