1 . After a particularly strong storm named Klaus hit southwestern France in 2009, researchers made a curious observation about the damage: nearly all the trees beaten up by winds blowing at speeds of 94 miles per hour, regardless of their species, height or diameter, however, most trees hit by strong winds below that were in good condition. Was this wind-speed threshold(分界线) really the arbiter(仲裁者) of destruction?

Physicist Christophe Clanet and his colleagues at France’s École Polytechnique and ESPCI Paris Tech set to find out by breaking beechwood rods(格木棒) of different lengths and diameters under controlled conditions. To do so, they inserted one end of a given rod into a hole of the same diameter in a block of steel and slowly added force to the other end, causing the rod to bend. Then they measured the critical figures to determine a corresponding wind speed. What they found matched the real-world situation of 2009: the calculated wind speed to break the rods—no matter the size was about 94 mph.

However, several outside experts have concerns about this. For example, Lee Frelich, director of the University of Minnesota Center for Forest Ecology, says that modeling trees as branchless cylinders(无分支气缸) ignores the streamlining (直线型化) of branches in the wind, which in turn changes the relation between force on the trunk and wind speed. In other words, the method did not reflect the complex interactions of real-life biology, weather and physics. Regardless, Clanet and his colleagues do think the results have utility and plan to study whether strong winds can change the breaking point.

1. How did Clanet conduct the study?

A．By setting plans and giving examples.

B．By collecting figures and using information.

C．By doing experiment and measuring figures

D．By analyzing data and drawing a conclusion.

2. What’s the attitude of Lee Frelich towards the study?

A．Optimistic.

B．Indifferent

C．Objective.

D．Worried.

3. What does the underlined word “utility” in Paragraph 3 mean?

A．Effect.

B．Usefulness.

C．Future.

D．Significance.

4. Which of the following is the best title for the passage?

A．How the wind cuts wood

B．Why the wind destroys wood

C．Wind speed: the changer of winds

D．Whether strong winds can change the breaking point

2 . Why It’s Hard to Lose Weight

What makes people gain weight? This seems like a simple enough question to answer. If we eat a lot and don’t do enough exercise, we will become fat.     1    

As we know, what we eat greatly affects our weight. It is widely accepted that people have 100% control over what they eat and how much they eat. This, however, is partly true.     2     You may rarely touch vegetables while overeating fried chicken. Meanwhile, the serving size and the background music can both affect how much we eat.

Our bodies themselves can decide whether we are more likely to gain weight or lose weight. Scientists have found that the more delicious the food, the more excited our brains get.     3     Compared to people of normal weight, fat people feel more excited when they see delicious   food.

Also, our bodies use a variety of hormones (激素) to tell our brains whether they are hungry or full.   Ghrelin(胃饥饿素), for example, tells the brain that the body wants food. Leptin(瘦蛋白), meanwhile, tells the brain that it’s time to stop eating. Ghrelin and leptin help us to maintain a healthy weight.     4     As we get fatter, the levels of leptin in our bodies rises.   Our brains are told not to eat all the time. In the end, they would no longer trust leptin and would stop responding to its “warnings”. When we start to lose weight, leptin levels drop. Our brains think we are hungry and makes us find food in our fridge.

    5     They may have tried very hard, but their bodies are working against their will.

A．But sometimes, they may work improperly.

B．People form habits around food at a young age.

C．If we often have delicious food, over time, our brain   will change.

D．Now you know why fat people often have a tough time losing weight.

E．There is also evidence to show industrial chemicals may increase body fat.

F．However, the science behind weight problems is more complicated than we think.

G．People with low levels of body satisfaction are more likely to gain weight over time.