题目

弃耕的农田很快长满杂草，几年后，草本植物减少，灌木出现并逐渐繁茂起来，继而出现乔木并逐渐长大，在此演替过程中，相关变化趋势正确的是（ ） A．群落演替的根本原因是受到外界因素的影响，尤其是人为因素 B．群落演替是一个种群被另一个种群替代的过程 C．群落演替过程中，生物的总光合量和总呼吸量逐渐增大 D．如果人为给弃耕农田施肥，不会改变演替的速度和方向阅读理解     An Englishman was showing a foreign visitor around London. "What's that strange building?" asked the visitor."That's the Tower of London." "I see. How long did it take to build it?" "About 500 years. " "In my country we canbuild it in five months," said the visitor.     Shortly after that they came to St. Paul's Cathedral (圣保罗大教堂). "Very interesting! " said the visitor. "Howlong did it take to build it?""Nearly 40 years," said the Englishman. "In my country we can finish it in 40 days,"said the visitor.     This went on all day. They visited most of the best known buildings in the city. Every time they saw a new one,the visitor asked what it was and how long it took to build it. Then he said that they could do the same thing muchfaster in his country. At last the Englishman got angry with the visitor, but he tried not to show it. Several days laterthey came to the House of Parliament (议会大楼) and the visitor asked his usual question, "What's that?" TheEnglishman answered, "I've no idea. It wasn't there last night. "1. The Englishman told the visitor it took _____ to build the Tower of London.A. about 500 yearsB. about five daysC. about five monthsD. about five years2. The visitor said that in his country it would take them _____ to build St. Paul's Cathedral.A. less than half a yearB. forty daysC. five hundred yearsD. thirty days3. It took them a few days to see _____.A. many of the best known sports in EnglandB. several best known places in EnglandC. many famous people in the city of LondonD. most of the famous buildings in London4. The Englishman was very angry at the end of the day, but he _____.A.didn't want to see anythingB. tried not to show the visitor around the cityC. had no time to tell the visitorD. tried not to let the visitor know it5. The Englishman's last answer showed _____.A. he didn't know how to tell the visitor its nameB. he was sorry that he hadn't seen the building beforeC. he could say nothing because he didn't know anything about itD. he was angry and didn't want to tell the visitor the name of the building