The Mississippi is the major river system in the United States. The Yangtze is China's longest river. Although a world apart, the two waterways share conservation concerns that provide a cultural bridge between students in the United States and China, as well as from around the world. The Mississippi flows almost 3,800 kilometers from a small lake in Minnesota, gathering the waters of 250 other rivers and streams before reaching the Gulf of Mexico. In mid-May, as spring flowers began to open, about 41 students from a dozen colleges, mostly in the Midwest, explored a section of the river in Wisconsin and Iowa, to learn about the environment, and each other. The students, from the U.S., China and around the world, came to join the River Spirit Exchange program. The cross-cultural educational experience - set up by the University of Wisconsin, Madison-based Environment and Public Health Network for Chinese Students - focuses on the Mississippi and China's longest river, the Yangtze. This three day get-together featured story-telling, hiking, camping and canoeing, all part of a larger lesson about conservation projects that can be used on both the Yangtze and Mississippi. While the students learned about the problems challenging the Mississippi and Yangtze, Jeb Barzen, a wildlife biologist, explained they should also learn about the importance of bridging each other's culture. The president of the Environment and Public Health Network for Chinese Students, Xiaojun Lu, said the Mississippi and Yangtze Rivers are uniting these students from opposite ends of the earth. Organizers say the success and spirit of this first gathering of students will lead to other trips, including one down the Yangtze. What is the passage mainly about? A) A major river system in the United States. B) The differences between the Mississippi and the Yangtze. C) An educational program about tourism. D) An international cultural exchange program.
D
(Question)
Most people have heard the sound of bees among flowers. Bees live almost everywhere in the world except in the Arctic areas. Many kinds of agriculture depend on these small, social insects. Without bees, fruit and nut growers as well as many other farmers would not have a crop. There are more than 20,000 kinds of bees. But only honey bees make enough honey for people to use. Honeybees are highly-organized social insects. They work together in a group, called a colony . Each colony lives in a hive . It contains one queen bee -- she lays all the eggs from which the members of the colony come. Each colony has only a few hundred males, called drones. The majority of all bees in a colony are workers, which are all females. Bees even have a special stomach, called a honey stomach, which is used to store sweet fluid that the bees gather from flowers. Bees also have long hairs on their body and legs. These hairs capture pollen as bees go from flower to flower. Some of the pollen is taken back to the hive. Some, however, is passed to the next flower. This is how many plants are fertilized. Pollen is the reproductive material of plants. Many important agricultural crops depend on bees for fertilization. Inside their hives, bees store sweet liquid from flowers and pollen as well. They may even gather sweet liquid from some other kinds of insects. These kinds of sweet liquid are also stored in the hive. Bees make honey through a process. They add liquid from their own mouths to sweet liquid into simple sugar. As the honey is stored, it dries. It becomes thicker and darker. Although bees are often thought of as honey makers, they provide a surprising number of products. Also, their greatest economic value is in fertilizing crops-not in making honey. The word "fertilize" in the sentence "This is how many plants are fertilized" probably means " _ ". A) to make plants strong and productive B) to make soil rich for plants C) to start the development of young flowers D) to introduce pollen into plants
(Answer)
D
Scientist Says 'No' to Human Cloning "I've never met a human worth cloning," says cloning expert Mark Westhusin from his lab at Texas A&M University. "It's a stupid endeavor." That's an interesting choice of adjective, coming from a man who has spent millions of dollars trying to clone a 13-year-old dog named Missy. So far, he and his team have not succeeded, though they have cloned two cows and a cat. They just might succeed in cloning Missy soon -- or perhaps not for another five years. Westhusin's experience with cloning animals leaves him upset by all this talk of human cloning. In three years of work on the Missy project, using hundreds upon hundreds of dog's eggs, the A&M team has produced only a dozen or so embryos carrying Missy's DNA. None have survived the transfer to a surrogate mother. The wastage of eggs and the many spontaneously aborted(,) fetuses may be acceptable when you're dealing with cats or bulls, he argues, but not with humans. "Cloning is incredibly inefficient, and also dangerous," he says. Even so, dog cloning is a commercial opportunity, with a nice research payoff. Ever since Dolly the sheep was cloned in 1997, Westhusin's phone has been ringing with people calling in hopes of duplicating their cats and dogs, cattle and horses. "A lot of people want to clone pets, especially if the price is right," says Westhusin. Cost is no obstacle for Missy's mysterious billionaire owner; he's put up $3.7 million so far to fund A&M's research. Contrary to some media reports, Missy is not dead. The owner wants a twin to carry on Missy's fine qualities after she does die. The prototype(;)is, by all accounts, athletic, good-natured and supersmart. Missy's master does not expect an exact copy of her. He knows her clone may not have her temperament(, ). In a statement of purpose, Missy's owner and the A&M team say they are "both looking forward to studying the ways that her clones differ from Missy." Besides cloning a great dog, the project may contribute insight into the old question of nature vs.... By cloning Missy, Mark Westhusin hopes to _ . A) study the possibility of cloning humans B) search for ways to modify its temperament C) find out the differences between Missy and its clones D) examine the reproductive system of the dog species
C