词汇网络: shad

A large natural flow of water that travels across land and into the sea or a lake. It is a moving body of water that usually starts in mountains or hills.

To cause something to come into existence, often in large numbers, or to produce offspring. It can refer to both living organisms and the creation of something abstract.

Migration is the movement of people or animals from one place to another to live or find food. It can happen every year with the seasons or be a permanent move to a new country.