小林家养一些鸡，黄鸡比白鸡少8只，白鸡的只数是黄鸡的2倍，则小林家养黄鸡8只，白鸡16只．

孙中山三民主义先生是伟大的民主革命先行者，他殚精竭虑地勾画中国社会的发展蓝图，并为之进行不懈的奋斗。

材料一  文明越发达，社会问题越着紧，……英国财富多于前代不止数千倍，人民的贫穷甚于前代也不止数千倍，并且富者极少，贫者极多。……美国官吏有由选举得来的，有由委任得来的。……无论是选举、是委任，皆有很大的流弊，就选举上说……美国代表院中，往往有愚蠢无知的人夹杂在内。

——孙中山三民主义《民族的、国民的、社会的国家》（1906年）

材料二   政是众人之事，集合众人之事的大力量，便叫做政权；政权就可以说是民权。治是管理众人之事，集合管理众人之事的大力量，便叫做治权；治权就可以说是政府权。所以政治之中，包含有两个力量：一个是政权，一个是治权。这两个力量，一个是管理政府的力量，一个是政府自身的力量。

——孙中山三民主义《三民主义·民权主义》

材料三  （欧、美）没有解决土地问题……解决的法子，社会学者所见不一，兄弟所最信的是定地价的法，比方地主有地价值一千元，可定价为一千，或多至二千，就算那地将来因交通发达价涨至一万，地主应得二千，已属有益无损；赢利八千，当归国家。这于国计民生，皆有大益。少数富人把持垄断的弊窦自然永绝，这是最简便易行之法。

——孙中山三民主义《民族的、国民的、社会的国家》（1906年）

材料四   国家当给佃农以土地，资其耕种……凡本国人及外国人之企业，或有独占的性质，或规模过大为私人之力所不能办者，如银行、铁道、航路之属，由国家经营管理之，使私有资本制度不能操纵国民之生计此则节制资本之要旨也。

——《中国国民党第一次全国代表大会宣言》

根据生活经验和所学知识判断，下列课外实验不能成功的是（　　）

    Radar is an electronic device that detects planes, ships, coastlines, landmarks, and even storm clouds. The name radar comes from the first letters of the words radio direction and ranging. As the human eye uses light waves to see, radar “sees” with radio waves. Without radar, planes could not land safely in bad weather and ships could not move safely in thick fog____

    In the 1800s it was discovered that radio waves could be reflected from objects. But scientists did not make great advances in radar research until the 1930s, when the world was threatened by war____ It has been used widely in almost every conflict since then.

    Echoes make it possible for radar to work. When a beam of radio waves is sent out, it strikes on an object and returns an echo. This echo is picked up by radar and recorded on a screen similar to television screen. On the screen an observer sees a flash, or a blip, that shows the direction and distance of the object.____

    Airport control towers use radar to guide planes in for safe landings. Almost all large ships depend on radar to prevent collisions with icebergs or other ships____Weather forecasters “see” the size, direction, and speed of storms on radar screens. Astronomers can even use radar to measure accurately the distance to the moon. Thus, the device has generated major advancements.

    ____Huge radar antennas have been installed all over the United States. They guard us against possible enemy attacks. We have ballistic—missiles (战略导弹)warning systems that can alert us to attacks when missiles are more than 1,000 miles away. Other radar systems warn us against enemy aircraft and even spying space satellites.

A. Police track speeders in radar-equipped cars.

B. These measurements are now highly accurate.

C. The device can be used in a wide range of fields.

D. It is therefore especially valuable to shippers and travelers.

E. During World War II many countries used radar effectively.

F. Today radar is used by commercial airliners and weather forecasters.

G. Strengthening national defense is one of radar's most important functions.