( )是指调控经济运行、实现国家规划和各种社会目标所需配套的一系列经济政策。A．经

如图所示，在直角坐标系的第一、四象限内有垂直于纸面的匀强磁场，第二、三象限内有沿x轴正方向的匀强电场，电场强度大小为E，y轴为磁场和电场的理想边界．一个质量为m，电荷量为e的质子经过x轴上A点时速度大小为v₀，速度方向与x轴负方向夹角为θ=30°．质子第一次到达y轴时速度方向与y轴垂直，第三次到达y轴的位置用B点表示，图中未画出．已知OA=L．

（1）求磁感应强度大小和方向；

（2）求质子从A点运动至B点时间．

长方形的长是a，宽是b，周长是C，面积是S．周长公式是：______．面积公式是：______．

属于子宫内膜癌前期病变的是（）

A.萎缩型子宫内膜

B.增生期子宫内膜

C.子宫内膜腺瘤型增生

D.子宫内膜腺瘤型增生过长伴细胞不典型增生

E.子宫内膜腺囊型增生过长

Watch a baby between six and nine months old, and you will observe the basic concepts of geometry being learned. Once the baby has mastered the idea that space is three-dimensional, it reached out and begins grasping various kinds of objects. It is then, from perhaps nine to fifteen months, that the concepts of sets and numbers are formed. So far, so good. But now an ominous development takes place. The nerve fibers in the brain insulate themselves in such a way that the baby begins to hear sounds very precisely. Soon it picks up language, and it is then brought into direct communication with adults. From this point on, it is usually downhill all the way for mathematics, because the child now becomes exposed to all the nonsense words and beliefs of the community into which it has been so unfortunate as to have been born. Nature having done very well by the child to this point, having permitted it the luxury of thinking for itself for eighteen months, now abandons it to the arbitrary conventions and beliefs of society. But at least the child knows something of geometry and numbers, and it will always retain some memory of the early happy days, no matter what vicissitudes it may suffer later on. The main reservoir of mathematical talent in any society is thus possessed by children who are about two years old, children who have just learned to speak fluently.

Which of the following activities would teach a baby about geometry().

A. Picking up language.

B. Communicating with others.

C. Recognizing numbers.

D. Catching different objects.

患儿，4岁。近日睡眠不宁，烦躁不安尿频，伴有搔抓阴部，食欲下降。舌淡苔白，脉无力。其治疗的方法是（）

A.驱蛔安神

B.杀虫止痒

C.调理脾胃

D.安蛔定痛

E.健脾理气