Explain why the lymphatic system is a one way system

Explain why the lymphatic system is a one-way system, whereas the blood vascular system is a two-way system. Blood vessels form a complete circuit from and to the heart. The lymphatic system lacks arteries and begins with blind-ended lymph capillaries. Thus, it is a "return" system only.

It settles nerves, reduces the tension.

I’m going to guess these are the choices: a) recreational skiing developed in the mid-19th century b) it was originally invented as a way of getting from place to place in snowy regions c) downhill skiing is currently the only common form of the sport d) it mostly evolved from snowshoeing- if that’s the cases then the answer would be c) downhill skiing is currently the only common form of the sport