In your body, the outside "tube" that surrounds a cavity and inner "tube" is derived from the see section 30.2 ( page 616) .

This "tube" is derived from the endoderm. The endoderm is the innermost germ layer present in the earliest stages of the developing embryo. These cells will go on to become the epithelial lining of many systems as the embryo further develops.

When the ball is rising up, it gains kinetic energy. when the ball reaches the very top, it will have all potential energy, until it falls back down and gains it kinetic energy. finally when you catch the ball or it falls back down, it would have gained its potential energy back.

I'm sorry to hear that. i will try to answer your other questions if it is within my ability. : )answers: my favourite colour is black.my favourite food is pasta.my favourite school subject is english, but i do also like lunch time.my least favourite subject is history as well as geography. i have currently garnered a quite equal hatred for both of the subjects.what about you? well, you for the points. : )