spring：
none:
- the season between winter and summer when leaves and flowers appear: the spring of 1993; in the spring; late/early spring
- something, usually twisted piece of metal, that will return to its previous shape after if has been pressed down
- water: a place where water comes up naturally from the ground: spring water
verb:
- if something springs back, open,, it moves quickly, suddenly with force.
springboard: something that helps you to start doing something.
- which in turn provided a springboard for development of ....
- similarly;
- is concerned with
- is a nontrival problem due to the wide variability of ...
- proliferation: a sudden increase in the amount or number of something, the very fast growth of new parts of a living thing,such as cells.