Read the article and select the best answer. Article: At night, bats fly through the air, catching hundreds of insects and other small animals. But during the day, they hardly move at all. Instead, bats pass the time hanging upside down from a secret spot. There are a couple of reasons why bats rest this way. First of all, it puts them in a position for takeoff. Unlike birds, bats can't fly into the air from the ground. Their wings don't produce enough lift to take off from a dead stop, and their hind legs are so small and underdeveloped that they can't run to build up the necessary takeoff speed. Instead, they use their front claws to climb to a high spot, and then fall into flight. During the hours when most enemies are active, bats gather where few animals would think to look and most can't reach. This allows them to disappear from the world until night comes again. There's also little competition for these resting spots, as other flying animals don't have the ability to hang upside down. Bats have a unique physiological adaptation that lets them hang around this way without using any energy. For you to hold your fist around an object tight, you contract several muscles in your arm, which are connected to your fingers by tendons ;as one muscle contracts, it pulls a tendon, which pulls one of your fingers closed. A bat's talons close in the same way, except that their tendons are connected only to the upper body, not to a muscle. To hang upside down, a bat pulls its claws open with other muscles. To get the talons to take hold of the surface, the bat simply lets its body relax. The weight of the upper body pulls down on the tendons connected to the talons, causing them to hold tight. Therefore, the bat doesn't have to do anything to hang upside down. Question: What is the passage mainly about? Options: A: The living habits of bats. B: How and why bats hang upside down. C: The importance of bats' hanging upside down. D: How bats use their energy at night.
B

Read the article and select the best answer. Article: China is a land of bicycles. At least it was back in 1992 when I traveled the country. Back then everyone seemed to be riding a bicycle. Millions of them, all black. Cars were rare. Yet since my arrival in Beijing last year, I've found the opposite is true. There are millions of cars. However, people still use their bicycles to get around. For many, it's the easiest and cheapest way to travel today. Bicycles also come in different colors---silver, green, red, blue, yellow, whatever you want. It's fun watching people biking. They rush quickly through crossroads, move skillfully through traffic, and ride even on sidewalks . Bicycles allow people the freedom to move about that cars just can't provide. Eager to be part of this aspect of Chinese culture, I decided to buy a bicycle. Great weather accompanied my great buy. I immediately jumped up on my bicycle seat and started home. My first ride home was orderly . To be safe, I stayed with a "pack" of bikers while cars on the streets came running swiftly out of nowhere at times. I didn't want to get hit. So I took the ride carefully. Crossing the streets was the biggest problem. It was a lot like crossing a major highway back in the United States. The streets here were wide, so crossing took time, skill and a little bit of luck. I finally made it home. The feeling on the bicycle was amazing. The air hitting my face and going through my hair was wonderful. I was sitting on top of the world as I passed by places and people. Biking made me feel alive. Question: Which of the following best describes the author's biking experience? Options: A: The author enjoyed showing off his biking skills. B: The author took great pleasure in biking. C: The author was praised by the other bikers. D: The author was annoyed by the air while riding.
B

Read the article and select the best answer. Article: The monitor "watches" deceleration (=slow down) and distance from a light - and "guesses" which cars are likely to break the Highway Code. Most importantly, the software can provide two seconds' warning if someone else is about to shoot across a crossroads - enough time for other drivers to hit the brakes. Jonathan How, the Professor of Aeronautics and Astronautics at MIT, says "smart" cars of the future may use the system to help drivers foresee and avoid potential accidents. The researchers tested the algorithm on data collected from an intersection in Virginia, finding that it accurately identified potential violators within a couple of seconds of reaching a red light -- enough time, according to the researchers, for other drivers at an intersection to be able to react to the threat if alerted . Compared to other efforts to model driving behavior, the MIT algorithm brought fewer false alarms, an important advantage for systems providing guidance to human drivers. The researchers report their findings in a paper that will appear in the journal IEEE Transactions on Intelligent Transportation Systems. Question: Which of the following statements is NOT the advantage of this algorithm? Options: A: It will raise the alarm when the driver breaks the traffic rules. B: It usually produces fewer false alarms. C: It helps drivers avoid potential accidents by judging the threats. D: The monitor of this algorithm can judge the traffic condition from the lights of other vehicles.
A