Hi, I read some papers about Calabi-Yau surfaces but I have some basic questions about them if you can answer them for me. 1. Who proved that Calabi-Yau mfds fits into string theory? Why does C-Y surface fit into string theory, instead of any other surfaces? 2. I googled C-Y surfaces and saw many beautiful pictures of them. But why do they look like that? Do you have explanation other than the fact that it has trivial canonical bundle? 3. What are different kinds of singularity types that can occur on a C-Y surface (just an intuition of them will be fine)? Why is the orbifold singularity considered to be the simplest singularity on C-Y surface? 4. Why do singularities form on C-Y surfaces and what physical meaning do they have? 5. Why should we resolute singularities? 6. An orbifold is locally C^n/G where G is a finite subgroup of SL(n,C). So where are the singularities? How do you see that? 7. What is a physics meaning of a canonical bundle? Thank you in advance for your time.