A：相互补给
B：河水补给潜水
C：潜水补给河水
D：互不补给
As we know, his father is a very famous scientist in physics. But what you don't know is that he _______ as a farmer for five years.
人工诱变育种的理论基础是____ ，常用的方法有物理方法，如用____ 、____ 、____ 、____ 等处理；化学方法如用____ 、____ 等处理．
