these books is well worth reading 句中的well是充当行容次修饰worth?

these books is well worth reading 句中的well是充当行容次修饰worth? Neither of these books is worth reading. What is worth doing is worth well. It was well worth the effort.句子中的worth是什么词性,充当什么句子成分 The book( )I spent 30 yuan is well worth reading It is __ reading this book carefully. A.worth B.well worth C The book is well worth reading 为什么不能用very代替well Whatever is worth _A__ at all is worth ___ well. Whatever is worth doing is worth doing well.怎么翻译? Whatever is worth doing is worth doing well. Whatever is worth doing at all is worth doing well.whatever是 a job worth doing at all is worth doing well.