Law in the Philippines

Briefly explain/answer the following questions.

1. What are thecharacteristics of contract of sales?

2. Can future goods can be element of sale? Why?

3. What are the obligations of seller?

4. What are the obligations of the buyer?

5. What are the effects of contract of sale if the thing sold is lost?

6. Is there a sale without a price?

7. Who is unpaid seller?

8. What are the three stages of contract of sales?

9. Can husband and wife enter into a contract of sale?

10. What is the legal importance of distinguishing between a contract of sale and a contract for a piece of work?