For thousands of years humans have used herbs , roots, and other things from nature to cure disease. Scientists looking for new cures often visit traditional healers. They find out what plants are used in healing. Then they look at what the plant contains. They find the active ingredient , which is the chemical in the plant that works to heal. Many of the drugs we use, including aspirin, have come from these natural medicines. In recent years, many people in the US have taking what are legally known as dietary supplements . They may be vitamins or minerals. They may be herbs that help with health problems, such as depression. Some of them are teas. Others are capsules or tablets. They are sold in natural food stores, drug stores, and groceries. Most people think that because these products are natural they are also safe. This is not always true. There are many plants that are poisonous. There are others that have bad side effects. The New England Journal of Medicine publishes medical research. A recent edition called for the government to _ dietary supplements. Several doctors wrote to the Journal and told of bad experiences people have had with dietary supplements. Dietary supplements aren't tested in the same way as drugs. There is not always proof that the supplement really does what it is supposed to do. There is also a problem with purity of the supplements. Supplements have been found to contain things that are bad for the body. For example, the California Department of Health found that of 260 herbs grown in China, one third contained heavy metals. These are minerals such as lead and mercury . They are very poisonous, even in tiny amounts. The scientists study the cures from the healers in order to _ . A) find out if the plant is poisonous B) find out what in the plant works to cure disease C) look for aspirin in the plant D) make sure that the plant can cure disease
B
The candidate who is longing for election to the highest office in the United States must be native-born American citizen who is at least 35 years old and who has lived in the United States for at least 14 years. The election course is complicated, and the road to the Oval Office is long. Potential candidates must present papers stating their intention to seek their party's recommendation; delegates then choose from among those running some months later at the national conferences. Before that, however, each state holds a primary election that determines how the state's voters want the party's delegates to vote. Methods of choosing the delegates vary from state to state. At the conferences, there are speeches and often heated discussions. It may take several rounds of voting before delegates can agree on a candidate. On the final day of the meeting, the presidential candidate announces his or her choice for vice president. Election Day, by law, is the Tuesday that follows the first Monday in November. On this day, registered voters may cast their votes for president, vice president, and candidates for other federal state, and local offices. The popular vote, however, does not determine who will be president. The president is chosen by a vote of the Electoral College, a group of 538 citizens from the 50 states and the District of Columbia who are chosen to cast votes for the president and vice president. The rules for choosing electors, as with the delegates, vary. Each state also decides whether its electoral votes must reflect the popular vote. The number of electors in each state is determined by the number of representatives and senators that a state sends to Congress and, therefore, may change every 10 years, depending on the results of the United States census . The winner must get at least 270 of the electoral votes when the Electoral College meets in December of the election year. The election results are not official, however, until the following January, when Congress meets in a joint conference to... Which of the following is not a requirement for candidates for the presidency of the USA? A) Minimum age of thirty-five years old. B) Native of the United States of America. C) Bottom residency of fourteen years in the State D) Previous experience in an elective office.
D
Q: Like most people, I was brought up to look upon life as a process of getting. It was not until in my late thirties that I made this important discovery: giving-away makes life so much more exciting. You need not worry if you lack money. This is how I experimented with giving-away. If an idea for improving the window display of a neighborhood store flashes to me, I step in and make the suggestion to the storekeeper. One discovery I made about giving-away is that it is almost impossible to give away anything in this world without getting something back, though the return often comes in all unexpected form. One Sunday morning, the local post office delivered an important special delivery letter to my home, though it was addressed to me at my office. I wrote the postmaster a note of appreciation. More than a year later I needed a post-office box for a new business I was starting. I was told at the window that there were no boxes left, and that my name would have to go on a long waiting list. As I was about to leave, the postmaster appeared in the doorway. He had overheard our conversation. "Wasn't it you that wrote us that letter a year ago about delivering a special delivery to your home?" I said yes. "Well, you certainly are going to have a box in this post office if we have to make one for you. You don't know what a letter like that means to us. We usually get nothing but complaints." When the author needed a post-office box, _ . A) he had put his name on a waiting list B) he wrote the postmaster a note of appreciation C) many people had applied for post-office boxes before him D) he asked the postmaster to make one for him
A: C
Q: America's greatest technological achievement, the Hoover Dam, now has a companion piece, a bridge held up by the longest arch in the Western Hemisphere . The Mike O'Callaghan-Pat Tillman Memorial Bridge, which opened this month and connects the U.S. states of Arizona and Nevada, crosses the vast chasm 890 feet above the Colorado River that is controlled by the dam. The striking 1,900-foot-long structure will improve traffic in the region and help protect the dam from being destroyed. It is the seventh highest bridge in the world, behind four in China, one in Papua New Guinea and one in the US state of Colorado. "The Hoover Dam is the greatest civil engineering achievement in America's history," said the bridge project manager Dave Zanatell. "Our goal was not to outdo or outshine it. Our goal was to, in a respectful way, do something that would be great for our generation and that would stand besides Hoover Dam in a respectful and quality way that would become a part of Hoover's legacy ." Just as the Hoover Dam was built in the heart of the Great Depression and was seen as an example of the nation's can-do spirit, some hope this project can also provide some _ . The bridge is surprising: at 1,050 feet, its support arch holds up a roadway that lies on 300-foot-long concrete pillars , some of the tallest in the world. It contains 16 million pounds of steel. The idea of the bridge came into being in the 1960s because the top of the Hoover Dam has been a narrow two-lane road that is the fastest route from Arizona to Las Vegas and then the Pacific Northwest and Canada. Access to the dam from each direction is a dangerously winding route, but massive trucks and passenger vehicles shared it for decades. During the day, when thousands of tourists travel to the dam from Las Vegas three times as many accidents as on a normal road will happen. The bridge has a sidewalk on the side facing the dam. The wall on both sides is 54 inches high, so walkers can take photos there. The text is mainly about _ . A) the Hoover Dam B) American western development C) a tour along the Colorado River D) a recently built bridge
A: D