题目

 “半叶法”测定植物光合作用强度，其基本过程是：如图将植物对称叶片的一部分（A）剪下置于暗处，另一部分（B）则留在植株上进行光合作用．一定时间后，在A、B的对应部位截取同等面积的叶片分别烘干称重，然后再计算出该植物光合作用的强度（单位：mg/dm2•h）． 实验步骤： （1）在田间选定有代表性的植物叶片若干片并编号． （2）叶子基部处理：为了确保选定叶片的     无法外运也不能运入，但又不影响          的供应，必须采 Celebrations spread across China when Shanghai, the Oriental Pearl, was given the right to host the 2010 World Expo on December 3. Shanghai won the honor after beating rivals from Russia, Mexico, Poland and South Korea. “I’m very proud of being Chinese,” said Wang Kaibo, a Senior 2 student of the Middle School Affiliated (附属的) to Beijing Medical University. “The winning of the expo is a victory, not only for Shanghai residents, but for the people of the whole Chinese nation.” Bidding for the expo shows that China is more confident of playing a more important role on the international stage. It’s competing for large events and the next one could be the World Cup, Wang said. The World Expo 2010 and the 2008 Beijing Olympics will become the twin shining stars of China’s development over the next 10 years, said experts. The World Expo is known as “Olympics of the economic, cultural, scientific and technological fields.” It is usually held every five years and lasts for six months. The Olympics, World Cup and World Expo are considered three top international events in the world. China is the first developing country to win the expo bid in the event’s about 159-year history. Not only will it attract more foreign investment to China, but experts say that the half-year-long exhibition will bring at least 70 million visitors to Shanghai. The expo was first held in London in 1851. It has a history of global influence. The Eiffel Tower, built during the Paris World Expo in 1889, became the symbol of the French capital. Many historic inventions, such as the telephone and airplane, all made their first appearance at a World Expo. 64. What does the word in bald “rivals” probably mean in the second paragraph? A. competitors.         B. enemies.            C. players.            D. supporters. 65. The winning of bidding for the World Expo 2010 and the 2008 Olympic Games implies ______. A. China is beginning to play a more important part on the international stage. B. China has played the most important role in the international affairs. C. China has become a developed country for many years. D. China is the first Asian country to win the expo bid in history. 66. As we know, in general, the Word Expo is usually held every ______ years, while the Olympics is usually held every ______ years. A. 4；5                B. 5；4                  C. 4；4                D. 5；5 67. By bidding for the expo and the Olympics, we are sure that ______. A. China will beat rivals from Russia, Mexico, Poland and South Korea B. China will become a super country in the United Nations C. China will build a famous tower like Eiffel Tower as the symbol of the capital D. China will develop more quickly than before and will benefit a lot from them