Hunting with birds is a very old sport. In some countries the golden eagles are used for hunting wild animals. They are used for hunting foxes and wolves.

    Training an eagle to hunt takes a long time. Hunters catch young eagles by using nets made of hair. After being trained, the eagle is taken to a field. A blindfold (眼罩) over the bird's eyes keeps it quiet until the hunter is ready.

    The eagle sits on the arm of me hunter. The hunter's arm is covered with a long, special glove to protect it from me sharp claws (爪子) of the bird. In the field, as soon as the hunter sees a fox or a wolf, he takes the blindfold off the eagle's eyes. The eagle quickly flies into the air and begins to look for the wild animal.

    The eagle sees the animal and catches it with claws like steel (钢铁). Its mouth and claws are strong enough to hold the animal. Usually, the bird carries the animal back to the hunter. Sometimes fast animals with good eyes can get away.

下图是植物细胞的基本结构模式图，请填出植物细胞的各种结构名称。

①____②____③____

④.____⑤____⑥____

如图所示，表面粗糙的斜面固定于地面上，并处于方向垂直纸面向里的磁场和竖直向上的匀强电场中，磁感应强度大小为B，电场强度大小为E．一质量为m、带电量为﹣Q的小滑块从斜面顶端由静止下滑，在滑块下滑过程中，下列判断正确的是（   ）