4．Have you ever heard of Iceland？Iceland is a country，one-tenth of which is covered with ice．However，it is said that Iceland is the land of heat．Smoking volcanoes （火山），white steam （蒸汽） and hot springs are more amazing than the other sights including ice there．
It has taken millions of years for volcanoes and lava flows （熔巖流） to build Iceland．When hiking through one of Iceland's many ancient lava fields，you may notice something strange．White steam is rising from each vent in front of you．Iceland is covered with vents which steam can pass out of．The steam comes from naturally heated rocks and hot water below the Earth's surface （表面）．
Like steam vents，hot springs can be seen here and there in the ancient lava fields．Blue Lake is the most famous hot spring in Iceland．It isn't far from the capital city of the country．The water and white earth in it can make your skin as soft as a newborn baby's skin．Enjoy that water，because it has traveled a long way．It starts nearly two kilometers under Blue Lake．There，water from the ocean continues moving up slowly into the spaces between hot rocks below the surface．And then the water is heated by hot rocks．Powerful machines and long pipes （水管） help bring the heated water to the surface．People in Iceland use natural hot water for hot springs．Besides，they use it to create electricity that can be used to heat homes and even greenhouses．
Iceland is one of the few places on the Earth where active volcanoes lie below ice．Heat from the volcanoes creates a strange and wild beauty．Therefore，some people believe that it's better to call the country"Heatland"instead of Iceland．If you have a chance to travel there，take it．
根據短文內容選擇最佳答案．
46．From the passage，B are the most amazing sights in Iceland．
A．smoking volcanoes and ice
B．smoking volcanoes，white steam and hot springs
C．heated rocks，hot springs and new lava fields
47．The underlined word"vent"in the passage means"C"in Chinese．
A．進入口 B．回流口 C．排放口
48．PictureA shows how Blue Lake is formed．
49．Which of the following is TRUE according to the passage？B
A．Iceland was built millions of years ago．
B．People in Iceland use natural hot water for hot springs and creating electricity．
C．Iceland is the only country where active volcanoes lie below ice．
50．The best title for this passage should beC．
A．THE HISTORY OF ICELAND
B．THE HOT SPRING OF BLUE LAKE
C．THE HEAT IN ICELAND．
