题目

如图所示，光滑水平面上有两个大小相同的钢球A、B，A球的质量大于B球的质量．开始时A球以一定的速度向右运动，B球处于静止状态．两球碰撞后均向右运动。设碰前A球的德布罗意波长为λ，碰后A、B两球的德布罗意波长分别为λ2和λ3，则下列关系正确的是    A．λ1=λ2=λ3          B．λ1=λ2+λ3    C．   D．. 　　China to sell yuan bonds (国库券) abroad 　　China has announced its first sale of government bonds yuan outside the mainland. 　　The government will sell 6bn yuan of bonds in Hong Kong to “improve the international status of the yuan,” the finance ministry said. 　　The sale is a milestone as China opens up its financial markets and promotes RMB as a world benchmark(基准点) . 　　Hundreds arrested in deadly Uganda riots(暴乱) 　　At least 640 people were arrested and 14 killed in fighting in Uganda’s capital between government forces and loyalists of a traditional kingdom. The number of people arrested for suspected roles in the three-day riots could go up because investigations are still under way, said Kale Kayihura, the nation’s police chief. 　 “French Spiderman” conquered the 88-story Petronas Towers in Kuala Lumpur 　　Now 47, Robert has climbed some of the tallest buildings in the world, typically without the aid of safety equipment. On Sept. 1, armed with nothing but the chalk on his hands and some good climbing shoes, the “French Spiderman” added the 88-story Petronas Towers in Kuala Lumpur to his impressive list—which now totals more than 70—of skyscrapers(摩天大楼) climbed up. 　　Motorway lights go out 　　The Highway Agency has decided to turn off lights at undisclosed locations between midnight and 5 a.m. from March. It has done so despite warnings from motoring groups and safety campaigners. Nine councils have already switched off some street lights or plan to do so to save money and cut carbon emissions (排放物). 64. We can learn from the passage that ____. 　A. China has sold 6bn yuan of bonds in Hong Kong   B. more suspected people will probably be arrested in Uganda C. about 654 people took part in the Uganda riots 　D. the riots will last another three days 65. How many skyscrapers has Robert conquered so far? 　A. exactly 47         B. over 70          C. about 88          D. less than 158 66. The disadvantage of turning off motorway lights includes ____. 　A. saving money          B. cutting carbon emissions 　C. causing safety problems  D. decreasing the number of cars 67. All of the fields are mentioned except____ . 　A. politics      B. health        C. traffic     D. people