Read the following article and select the best answer. Article: On July 1 at exactly 7:59:59, Bejing time, the world' s atomic clocks will pause for a single second, or, more precisely, change to the unusual time of 7:59:60. The addition of a leap second , is to keep our clocks in time with the slowing of Earth' s rotation and astronomical time as measured by the sun. Just one extra second could affect the way computers and websites work, however. When the last leap second was added back in 2012, the community website Reddit crashed. For Reddit, the problem was that a Linux system got confused when it checked the network time and found an extra second. Speaking to Wired about the problem back in 2012, Linux creator Linus Torvalds commented:"Almost every time we have a leap second, we find something. It' s really annoying, because it' s code that is almost never used, and thus not tested by users under their normal conditions. " Companies have thought of their own solutions, and Google' s"leap smear"may be the best- known example. As company engineer Christopher Pascoe explains in a blog post, companies usually try to turn back the clocks by one second at the end of the day so that they play that second again. However, Pascoe believes this creates problems. He asked:"Does email that comes in during that second get stored correctly?"Google has a solution: Cut the extra second into milliseconds and then put these tiny amounts of time into the system throughout the day."This means that when it became time to add an extra second at midnight."Says Pascoe."Our clocks have already taken this into account over the course of the day." For many companies without Google' s money, however, the leap second will likely still cause some crashes. Question: What' s Pascoe' s attitude toward Google' s solution to the problem? - Ambiguous. - Approving. - Doubtful. - Cautious.
Approving.

Read the following article and select the best answer. Article: If you look outside, you probably will see some kind of insect. If your first instinct is to kill it, take a moment to think about all of the benefits insects provide to the environment. Entomologists, scientists who study insects, estimate that there are more than 800,000 species of insects found throughout the world. Only a few hundred of these insects are considered harmful. Mosquitoes, for example, are considered harmful. They bite humans and other animals, and their bites can cause skin pain and spread disease. Desert locusts also are considered harmful because they destroy crops causing billions of dollars in damage each year. However, the number of helpful insect species far outweighs the number of harmful species. Some insects make up a vital part of the food chain. Many different birds, reptiles, fish and even plants eat insects. There are also about 500 insects that people in various parts of the world eat. These insects are considered delicious food and prized for their high protein, mineral, and vitamin content. Other insects produce valuable commercial products such as silk, wax, and honey. Of all the insects, perhaps the most important are those that travel from flower to flower and pollinate the plants they visit. Agriculture around the world would be very different without the bees, butterflies, moths, flies and wasps that pollinate many crops. In fact, nearly one-third of the food you eat depends on plants that are pollinated by insects! While it is true that some species of insects harm or annoy us, _ . You may be destroying one of the hundreds of thousands of insects that provides many benefits to human beings. Question: According to the passage, insects are eaten in some parts of the world because _ . - they are nutritious - they are available to cook - they are easy to breed - they are free
they are nutritious

Q: Read the following article and select the best answer. Article: Researchers at San Diego Zoo have been studying what has been described as the "secret language" of elephants. They have been monitoring communications between animals that cannot be heard by human ears. The elephant's call will be familiar to most people, but the animals also give out growls . Their growls, however, are only partly audible ; two-thirds of the call is at frequencies that are too low to be picked up by our hearing. To learn more about the inaudible part of the growl, the team attached (......) a microphone sensitive to these low frequencies and a GPS tracking system to eight of the zoo's female elephants. The researchers could then relate the noises the animals were making to what they were doing. Matt Anderson, who led the project, told BBC News, "We're excited to learn how they interact and contact with one another." The team has already learned that pregnant females use this low frequency communication to announce to the rest of their long gestation of over two years, in the last 12 days we see the low part of the growl, which we can't hear. This we believe is to announce to the rest of the herd that the baby is upcoming," said Dr Anderson. The researchers believe that this also warns the elephants to look out for coming danger. "You may think that a baby calf of about 300 pounds would not be as open to predation as other species," he says. "But packs of hyenas are a big threat in the wild." Female elephants are only in season for around four days every four years and these calls can be heard by males more than two miles away. Question: Why some elephants' call is called "secret language"? - Because it can't be heard by human ears. - Because it can only be heard by female elephants. - Because people don't know its meanings. - Because people haven't studied it completely.
A: Because it can't be heard by human ears.

Q: Read the following article and select the best answer. Article: Now,I'll tell you something about the Internet.The Internet is a network of computers.It became popular in the 1990s.Now,we live in the Internet Age.The Internet is very useful.You can get information,do some shopping or talk with people all over the world.You can do all these things in your own room. You can set up your own space on the Internet.We call it a homepage.It's open to anyone in the world.Write your message on your homepage.Soon,you can get answers by email from people around the world. The Internet is also useful when a flood or an earthquake happens somewhere in the world.We can learn about the needs of the people there and send them food and medicine more quickly than before. In the world of the Internet,everyone is equal.Famous writers,artists,and scientists--they are all your friends.A lucky person can even find a message from the president of a country. Some people lose themselves in the world of the Internet.That's really bad.Remember that the world of the Internet is not a real world.Facetoface communication with family,friends,and neighbours is very important.Don't forget that the Internet is only a tool for communication and information. Many people say that the Internet has some problems,but most people agree the Internet still has a wonderful future.For the first time in history,anyone can exchange messages and information immediately with other people. Question: According to the passage,the Internet is usually used _ . - to get information from all over the world - to help people who need help badly - to react to email from all over the world - both A and B
A: both A and B