Here are the sentences transformed into passive voice, along with a brief explanation.

1. Shakespeare wrote Hamlet.
**Hamlet was written by Shakespeare.**
(In passive voice, the focus is on the action done to the subject.)

2. Mary chose this book.
**This book was chosen by Mary.**
(The emphasis is now on the book rather than Mary.)

3. I will organize the party.
**The party will be organized by me.**
(The subject receiving the action—the party—takes precedence.)

4. Amy invited me to the movie.
**I was invited to the movie by Amy.**
(The focus shifts to the person receiving the invitation.)

5. An earthquake hit Indonesia.
**Indonesia was hit by an earthquake.**
(Here, Indonesia is now the subject receiving the action.)

6. My cat didn't kill the mouse.
**The mouse wasn't killed by my cat.**
(Introducing the negative form, focusing on the mouse.)

7. Water surrounds an island.
**An island is surrounded by water.**
(The island becomes the subject, receiving the action of being surrounded.)

8. The students baked the cookies.
**The cookies were baked by the students.**
(This shifts the focus to the cookies rather than the students.)

9. We built the tree house.
**The tree house was built by us.**
(The tree house is now highlighted as the subject.)

10. The boys didn't break the window.
**The window wasn't broken by the boys.**
(This also shifts to the window in a negative context.)

Remember, in passive voice constructions, the form of the verb "to be" is aligned with the tense of the original active sentence, followed by the past participle of the main verb.