I had always assumed that the reason a squirrel had a big bushy tail was that as they careened through the space between branches they used it to wave around and keep from tumbling out of control.
我一直以为，松鼠有个毛茸茸的大尾巴，是因为它们摇晃着通过树枝间的空隙时，要摇摆它，以防失控跌倒。
2
Once they hit their first part of clean water flowing straight from the sea, the mum gave us a wave with her tail and off they swam into the distance.
一旦他们达到他们的清洁流动水从海直的第一部分，母鲸给了我们一个她的尾波，她们就在远方游去。
3
A practical calculation method is given. With the parameters of the impulse circuit the wave front and tail and the voltage efficiency can be calculated.