For 我的书呢? I would say: "What happened to my book?" rather than: "Where is my book?". Because the book may no longer exist. For example, translating 树呢? as "Where is the tree?" probably makes no sense. If the tree is not in its usual place, it probably no longer exists as a tree.
Is there a lesson on the sixth question, 了吗,,Do you use a verb, this is not clear to me I did not understand Question 9 Why is it clear😭😭😭 怎么样 At the end of the sentence change from a question What do you think right?
About 了吗, any verb + 了吗 means did you do this action? Or have you done it yet? You eat 了吗?(did you eat?) You do homework 了吗? (Did you do homework? So to answer your question, a verb is needed in this type of question.
About 怎么样,you are right. You can say a sentence and say 怎么样, meaning what do you think about what I just said. It’s usually used to give suggestions. We go to see a movie, 怎么样?