Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

    After the United States purchased Louisiana from France and made it their newest territory in 1803, President Thomas Jefferson called for an expedition to investigate the land the United States had bought for $15 million. Jefferson’s secretary, Meriwether Lewis, a woodsman and a hunter from childhood, persuaded the president to let him lead this expedition. Lewis recruited Army officer William Clark to be his co-commander. The Lewis and Clark expedition led the two young explorers to discover a new natural wealth of variety and abundance about which they would return to tell the world.

    When Lewis and Clark departed from St. Louis in 1804, they had twenty-nine in their party, including a few Frenchmen and several men from Kentucky who were well-known frontiersmen. Along the way, they picked up an interpreter named Toussant Charbonneau and his Native American wife, Sacajawea, the Shoshoni “Bird Woman” who aided them as guide and peacemaker and later became an American legend.

    The expedition followed the Missouri River to its source, made a long portage overland though the Rocky Mountains, and descended the Columbia River to the Pacific Ocean. On the journey, they encountered peaceful Otos, whom they befriended, and hostile Teton Sioux, who demanded tribute from all traders. They also met Shoshoni, who welcomed their little sister Sacajawea, who had been abducted as a child by the Mandans. They discovered a paradise full of giant buffalo herds and elk and antelope so innocent of human contact that they tamely approached the men. The explorers also found a hell blighted by mosquitoes and winters harsher than anyone could reasonably hope to survive. They became desperately lost, then found their way again. Lewis and Clark kept detailed journals of the expedition, cataloging a dazzling array of new plants and animals, and even unearthing the bones of a forty-five-foot dinosaur.

          When the party returned to St. Louis in 1806 after travelling almost 8,000 miles, they were eagerly greeted and grandly entertained. Their glowing descriptions of this vast new West provided a boon to the westward migration now becoming a permanent part of American life. The journals written by Lewis and Clark are still widely read today

The word “they” in paragraph 3 refers to ______.

A. elk and antelope 

B. buffalo herds

C. the members of the expedition 

D. Shoshoni and Mandans

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

What is “extreme” weather? Why are people talking about it these days? “Extreme” weather is an unusual weather event such as rainfall, a drought or a heat wave in the wrong place or at the wrong time. In theory, they are very rare. But these days, our TV screens are constantly showing such extreme weather events. Take just three news stories from 2010: 28 centimetres of rain fell on Rio de Janeiro in 24 hours, Nashville, USA, had 33 centimetres of rain in two days and there was record rainfall in Pakistan.

The effects of this kind of rainfall are dramatic and lethal. In Rio de Janeiro, landslides followed, burying hundreds of people. In Pakistan, the floods affected 20 million people. Meanwhile, other parts of the world suffer devastating droughts. Australia, Russia and East Africa have been hit in the last ten years. And then there are unexpected heat waves, such as in 2003 in Europe. That summer, 35,000 deaths were said to be heat-related.

So, what is happening to our weather? Are these extreme events part of a natural cycle? Or are they caused by human activity and its effects on the Earth’s climate? Peter Miller says it’s probably a mixture of both of these things. On the one hand, the most important influences on weather events are natural cycles in the climate. Two of the most famous weather cycles, El Niño and La Niña, originate in the Pacific Ocean. The heat from the warm ocean rises high into the atmosphere and affects weather all around the world. On the other hand, the temperature of the Earth’s oceans is slowly but steadily going up. And this is a result of human activity. We are producing greenhouse gases that trap heat in the Earth’s atmosphere. This heat warms up the atmosphere, land and oceans. Warmer oceans produce more water vapour – think of heating a pan of water in your kitchen. Turn up the heat, it produces steam more quickly. Satellite data tells us that the water vapour in the atmosphere has gone up by four percent in 25 years. This warm, wet air turns into the rain, storms, hurricanes and typhoons that we are increasingly experiencing. Climate scientist, Michael Oppenheimer, says that we need to face the reality of climate change. And we also need to act now to save lives and money in the future.

The word -lethal‖ in the second paragraph probably means ______.

A. far-reaching

B. long-lasting

C. happening soon

D. causing deaths