用于获得字符串S最左边4个字符的函数是______。

阅读理解。

     Basketball stars are usually tall. The stars of other sports are sometimes short. Some of the best football

players are not very tall.

     Short people often have better balance than tall people, so they do not fall over (摔倒) very often. In some

sports the players must have good balance, for example, table tennis and running.

     You do not need long legs to run fast! Some of the fastest runners in the world are not very tall. Some are

tall and some are short. There is no medicine to make people grow taller or to make people shorter.

     The tallest woman in the world is Sandy Allen. She is 2.317 meters tall and lives in the United States.

     The shortest person in the world is Gul Mohammed from India. He is only 57 centimeters (厘米) tall.

     Today young people in many countries grow taller than their parents. This is because they eat better food

today. Good food can help children grow.

1. How many different sports do we talk about in this passage (段落)? What are they?

   ____________________________________________________________.

2. Is there any medicine to make people grow taller or to make people shorter?

   ____________________________________________________________.

3. The tallest person in the world is ________ meters taller than the shortest one.

4. _______ _______ helps young people today grow taller than their parents.

5. 将短文中画线的句子译成汉语：

   ___________________________________________________________.

上尿路结石血尿的特点是

A．初始血尿

B．终末血尿

C．活动后血尿

D．无痛性血尿

E．全程血尿

第16届亚运会于2010年11月12日至27日在中国广州举行，同时也向世界展示了岭南文化的魅力。

回答1—2题。

1、有关地域文化的叙述正确的是 [ ]

A、珠江水和白云山是广州地域文化的代表

B、粤语、粤菜不属于岭南地域文化的范畴

C、地域文化是自然和人文因素综合作用的产物

D、广州现代城市建筑已不受地域文化的影响

2、亚运会举办期间，亚洲下列地区的地理现象正确的是 [ ]

A、亚洲各地区昼渐短、夜渐长

B、东亚地区受亚洲高压影响日益增强

C、南亚地区河流普遍进入结冰期

D、西亚地区进入了一年中的多雨时期

监理单位发现安全事故隐患未及时要求施工单位整改或者暂时停止施工的，有关部门应对其处以( )罚款。

A．3万～5万元
B．5万～10万元
C．10万～15万元
D．10万～30万元

影响磨损过程的外界因素是什么？