题目

表示下列反应的离子方程式正确的是（ ） A . 铁溶于稀盐酸：2Fe+6H+=2Fe3++3H2↑ B . 氯化铝溶液中加过量氨水：Al3++3NH3•H2O=Al（OH）3↓+3NH4+ C . 碳酸氢铵溶液中加足量氢氧化钠并加热：NH4++OH﹣H2O+NH3↑ D . 氯气通入水中，溶液呈酸性：Cl2+H2O⇌2H++Cl﹣+ClO﹣ 答案：B12．Most tourist destinations around China are witnessing travel peaks during the eight-day Mid-Autumn Festival and National Day holidays that run through Sunday．In Beijing，the Palace Museum，or the Forbidden City，attracted 182，000 tourists on Tuesday，the biggest number on a single day，as millions of visitors arrived in the national capital．"We saw absolutely nothing but people's heads，''said Guo Zhijun，42，of Henan province．"We wanted our 11-year-old son to learn something from the trip，but we only ended up very tired．"    Earlier，from Sunday noon to midday Monday，garbage collected at Tian'anmen Square in the heart of the city amounted to 7.9 tons，a quarter more than that in the same period of last year．    In the eastern coastal city of Qingdao，its top five major tourist sites attracted more than 200，000 visitors on Tuesday．    Yesterday，thousands of cars jammed two 20-kilometer mountain roads winding to and out of the Lushan Mountain scenic area in the eastern province of Jiangxi．The area，with about 3，000 car parking spaces，was unable to contain at least 8，000 inbound cars，said head of the Lushan Mountain public security bureau．    The Lushan Mountain tourism administration temporarily stopped selling entrance tickets to prevent the traffic from growing on Tuesday afternoon．Similar measures could be taken during the rest of the holidays，a police officer said．    Emergency measures have been taken at other scenic sites．Crowded visitors overwhelmedthe capacity（承载量）of the cable cars at Huashan Mountain，in Shaanxi province，leaving tens of thousands stuck at the peak late into Tuesday night．According to China Central Television，restless visitors demanded refunds from the tourism committee，and a lot of visitors had to give up and walk down the mountain．    Chen Li，deputy director of the Shaanxi Provincial Public Security Department，said on his micro blog that more than 300 policemen and government officials climbed up the mountain to help trapped visitors．Fearing that tourist sites might become too crowded，many people are staying at home，going shopping or making short suburban trips．A resident Mr．Wang in Nanchang，capital of Jiangxi，canceled long-distance travel plans after learning of heavy traffic on many highways during the first two days of the holidays．Instead，Wang，his wife and son went fishing in the suburbs before having a picnic．47．What happened in the Forbidden City that Tuesday？AA．There were far more visitors coming than expected．B．A large number of zones were opened to the visitors．C．Over 7.9 tons of garbage was collected．D．More than 200，000 visitors gathered there．48．What does the underlined word"overwhelmed"mean in paragraph 6？CA．showed up    B．added to    C．reached beyond    D．filled in49．The writer wrote this article toC．A．advise traveling to different places to learn somethingB．warn people not to climb those mountains on holidaysC．encourage people to change the travel plans according to the trafficD．suggest we stay at home or go shopping during those holidays50．Which of the following might be the best title？BA．Experiences from Different Travel PlansB．Travel Peaks in China's Tourist SitesC．Floods of People to the Forbidden CityD．Problems with Travelling on Holiday．