题目

如图所示为远距离输电的原理图，升压变压器和降压变压器均为理想变压器，发电厂的输出电压恒定、输电线上的电阻不变。若在傍晚用电的高峰期，则可以判定（ ） A . 发电厂的输出功率不变 B . 输电线上的损失功率增大 C . 输电线路上损耗的电压减小 D . 用户获得的电压增大 答案：BGreece declared a national state of emergency on Saturday as scores of forest fires that have killed at least 46 people continued to burn out of control, leaving some villages trapped within walls of flames, cut off from firefighters. Although most of the fires have been on the Peloponnesian Peninsula, some broke out on the outskirts of Athens on Saturday, forcing the evacuation of homes and closing a major road linking the capital to the main airport for several hours. The national fire brigade said that by evening it had brought those blazes under control, including one that came within about six miles of the city. The country has been helpless to fire this summer because of drought and three consecutive heat waves that sent temperatures high over 100 degrees. More than 3,000 forest fires have destroyed thousands of acres of wooded areas since June; the earlier fires killed nine people. The latest wave of fires on the peninsula started Friday. Strong, hot winds have spread the flames. Firefighters expect the death toll to rise, because they have not yet been able to search some areas that had been overrun by flames. Hardest hit by the fires were a dozen small villages around the town of Zaharo in the western peninsula, where at least 12 people, including some who may have been trying to flee by car, were killed. Scores of other residents, including elderly and disabled people, remained trapped in their homes, phoning into local television and radio stations, crying for help. Late Saturday, Mr. Karamanlis, Prime Minister of Greece appeared on national television and declared that he was mobilizing all of the country’s resources to control the fire. Mr. Karamanlis also suggested that the recent fires might have been purposely set. “So many fires sparked at the same time in so many regions is no coincidence,” he said, “We will get to the bottom of this and punish those responsible.” The overstretched national fire services are being helped by an estimated 6,000 soldiers mobilized for the operation. A fleet of water-dumping aircraft was expected from France, Germany and Norway, after Greece appealed to the European Union for “urgent assistance.” The writer mainly wants to tell us that ______ in the passage. A. firefighters battles fearlessly in Greece to control the fire B. constant fires in Greece have caused great life and wealth lose C. Greece is facing great danger as forest fires continue to break out D. Greek government is investigating the cause of recent forest fires According to the passage, which of the following might not contribute to the recent forest fires in Greek? A. Storm thunders in summer                           B. Lack of rainfall C. Extremely hot weather this summer            D. Hot and strong wind We can learn from the passage that ______. A. now the fire crisis in Greece has come to an end B. assistance from EU members is expected to come to help Greece C. firefighters in Greece so far can still manage the situation D. the number of people who die in the fire is expected not to rise any more Mr. Karamanlis believes the forest fires in Greece _______. A. is a happening by chance                    B. is a natural disaster C. might be caused by human on purpose   D. is a punishment of nature