当我正在拍摄它们的时候，领头的海狮直立起来，四周看了看，然后直朝着海滩方向快速游去了，整群海狮也跟过去了。

While I was photographing them, the leader of the group stood straight up and looked around and then swam straight and fast for the beach with the entire group following.

youdao

板的下半截要双的，上半截要整的，直顶到第一个环子；两块都要这样做两个拐角。

At these two corners they must be double from the bottom all the way to the top, and fitted into a single ring; both shall be like that.

youdao

PID参数整定与优化一直是自动控制领域研究的重要问题。

PID parameter tuning and optimizing is an important issue in the field of automatic control.

youdao