四、閱讀測驗【請在下列各題中選出最適當的答案】    Most people will never see a volcano erupt, but volcanoes are not the only way that the earth lets out itsinner energy. Hot springs are smaller, gentler ways to allow people to enjoy the earth ’s interior heat. Hotsprings are found where hot underground water flows up from the ground. The water is heated far below theground by magma. Because heated water can hold more dissolved solids, hot springs often contain a lot ofminerals. Some people believe that these mineral waters are good for their health. For example, they believethat sulfur relieves nasal congestion, calcium helps circulation, and salt water improves digestion. Not all ofthese healing properties have been scientifically proven. However, there are increasingly more studies tosuggest that soaking in a hot mineral spring can decrease arthritic pain.   The countries most famous for hot springs are New Zealand, Iceland, and Japan. New Zealand has morethan two dozen popular hot spring areas. Iceland, on the other hand, has about 800 hot springs in 250 areasaround the country. Iceland’s largest hot spring, Deildartunguhver, has a flow of 150 liters of boiling water persecond. Japan boasts about 3,000 hot spring resorts. In Japan, going to hot springs for relaxation is a nationalpastime. The energy inside the earth is unimaginable. It can make mountains explode, and yet it can alsoprovide relaxing, healing waters. That is something to think about the next time you are enjoying your hotspring.
44. Which of the following is the main idea of the passage?
(A) Hot springs are dangerous, but heal many diseases.
(B) Hot springs are formed after volcanoes erupt.
(C) Hot spring resorts are destroying the nature.
(D) Hot springs give many benefits to human beings.