题目

一只灯泡的额定电压为220V，为了确定该灯泡的额定功率；下述方案中最佳者为：     A．接入220V电路中使之正常发光，再与有标记的灯泡比较亮度进行判断     B．在实验室里用伏安法测出灯丝电阻，再用公式P=U2/R进行计算     C．接入220V电路中，测出通过灯泡的电流I，再用公式P=UI进行计算     D．直接与其它标有220V的灯泡从外观上比较确定When humans and nature go head to head, nature often ends up losing. Rivers get polluted. Trees are knocked down. Natural resources are exhausted. That’s what makes the Galapagos Islands so special—it’s one of he few places on the Earth that nature can truly call its own.For people used to having wild animals run at the scent of humans, a visit to the Galapagos is a real eye-opening experience. Over 1,600 km west of Ecuador, the islands are home to a unique variety of animals that have absolutely no fear of people. Visitors can play on the beach with sea lions and giant sea turtles, swim with dolphins and whales, and get close enough to the penguins to count the eggs in their nests.The islands were declared a national park over 40 years ago, and the number of human visitors is tightly limited to avoid damaging he environment or putting stress on the animal. Tourists have to pay a $100 daily visitors fee, and can’t step off the boat unless accompanied(陪同) by an official guide. Once on the islands, you have to stay on the trail(小径), but that seldom presents a problem: the animals are so curious about people that they’ll usually come up to say hello.“It’s a little like being in a zoo,” said one traveler. “But instead of us looking at the animals, the animals, the animals are looking at us.”Aside from the wildlife, one of the island’ more unusual features is its post office. You can send postcards for free, but the problem is that there’s no postman to collect them. Instead, travelers pick up mail addressed to people who live near them back home, and then hand-deliver the postcards when their trip is finished.1.The Galapagos Islands are .A. terribly polluted B. near EcuadorC. in the Atlantic Ocean D. independent of Ecuador2.Which animal is NOT mentioned in the passage?A. Whales. B. Sea lions.C. Goats. D. Dolphins.3.On the Galapagos Islands the mail is delivered by .A. the government B. the post officeC. the tourists D. the guides4.What would be the bet title for the passage?A. Special “Zoo” B. Humans and NatureC. Go Head to Head D. Ecuador—An Island Country5.What is one of the islands’ more unusual features?A. There’re some postmen to collect letters.B. There are only the wild life.C. You can send letters.D. Travellers deliver the letters by themselves.