实现表之间临时联系的命令是 【7】 。

Here is my idea about how a friend is like. Firstly, 61.______a friend is someone you can share your secrets. If you 62.______tell him a secret, never will he talks about it with anybody 63.______else. Besides, a friend is always good listener when you 64.______need one. After hear your sad stories, he will say some 65.______words that is nice and warm. Still, your happiness makes 66.______him happily, too. What’s more, a good friend is willing to 67.______offer the help to which you need, or can at least give you 68.______some advices. In a word, friends are those you like and 69.______trust, and you will enjoy every minute that you spent with 70.______them.

61().

如图是利用闪光照相研究平抛运动的示意图．小球A由斜槽滚下，从桌边缘水平抛出，当它恰好离开桌边缘时，小球B也同时下落，闪光频率为10Hz的闪光器拍摄的照片中B球有四个像，像间距离已在图中标出，单位为cm，如图所示，两球恰在位置4相碰．则A球离开桌面时的速度______．

读下图，回答问题。(10分)

（1）我国年降水量的地区分布规律是____________。

（2）①②③④四条河流中，属于内流河的是_______，属于外流河的是________。由图中看出，我国内流河多分布在__________。

（3）长江在A、B附近河段水能资源丰富，原因是__________。

（4）从水量、汛期两个方面比较长江和黄河水文特征的差异。

（5）我国水资源在地区分布上具有显著的不均衡性，南水北调工程将把长江流域的水调入华北、西北地区。试简述南水北调的重要意义。

黄连解毒汤的功用为（）。

工程后是否有必要再次到用户那里拜访？意义何在？