system engineering methods need 1000 words very fast

Please complete the following discussion points per syllabus:

1) What are some characteristics of a human-made or engineered systems that distinguish it from a natural system?

2) Pick a product, describe the enabling system that is requried to bring it into being, and explain the importance of engineering the system and product together.

3) As best you can, identify life-cycle activities that occur in the water fall model, the spiral model, and the "vee" model. Of these models, pick the one you perfer and explain why.