At about 3:00 am on July 28, 1976, a destructive earthquake     1     (shake) Tangshan, causing great suffering. The earthquake     2     (feel) even in Beijing, which is a long way away. In the     3     (frighten) 15 seconds, the whole city was gone, leaving people homeless and children     4     parents. Everywhere you looked, buildings fell down. Water, food and electricity were hard     5     (get). Soon after the quake,     6     (thousand) of soldiers were sent to dig out those     7     (trap) under ruins and bury     8     dead. Construction workers built shelters for the sufferers     9     homes were in ruins. Luckily for the     10     (survive), with flood of help from all over the country, the city began to breathe again.

4 . The cotton harvest is about to get underway in the Texas High Plains, the windswept region that grows most of the crop in the nation’s top cotton-producing state. But Barry Evans, a third-generation cotton grower, has already walked away from more than 2,000 acres (英亩) of his bone-dry fields. “It just didn’t come up. We hardly had anything,” said Evans.

Extreme heat and a lack of rainfall have severely damaged much of this year’s cotton harvest in the U.S., which produces about 35% of the world’s crop. The U.S. Department of Agriculture (USDA) forecast that more than 40% of what U.S. farmers planted in the spring would be abandoned because of drought. Nowhere is this more apparent than the flat, dry stretch of Texas. The USDA says Texas cotton farmers are likely to abandon nearly 70% of their spring planting. That has been the worst harvest since 2009.

The region normally receives around 18 to 20 inches of rain per year, but saw less than three inches of rain from August through the summer, as nearly all of Texas baked under drought. Much of the cotton grown in the region needs rain. Even those with irrigated (灌溉的) fields are expecting low yields (产量) this year.

The losses in cotton could cost the Texas High Plains $1.2 billion after farmers receive federal (联邦的) crop insurance payments, estimates Darren Hudson, director of the International Center for Agricultural Competitiveness at Texas Tech University. That leaves out others who depend on the crop, such as cotton gins (轧棉机) and storehouses. “Any time you have a bad year in cotton, it has a role to play in the overall economy,” Hudson said.

Fortunately, most cotton farmers in this part of Texas plan to use cotton seed varieties that can resist drought. Varieties are continuously developed and will be adjusted to generate high yields if dry conditions continue. “Even though it’s drought resistant,” Hudson added, “we still have to have a little bit of help from Mother Nature.”

6 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

In recent years, the world     1     (see) a number of natural disasters: hurricanes in the Caribbean and southern U.S., earthquakes in Mexico, and monsoons (季风雨) in southern Asia. These     2     (event) brought damage to communities. They also brought questions about what we can do to prepare     3     (we) for similar events. The best thing to do when facing a coming natural disaster is to pay attention to your area’s evacuation notices and take advantage of evacuation help. However, it’s possible to     4     (catch) by an unexpected emergency. When     5     (face) with those situations, what should you do to stay safe? How can you be better prepared? Every family should have an emergency plan     6     addresses the most likely disasters in their area. Practical     7     (survive) skills should also be part of every family’s plan. These skills need to be learned and practiced before things get hard. This is because you     8     (simple) won’t have time to read a survival book during     9     emergency.     10     (stay) calm is the most important thing a person can do during any emergency. A little fear is a natural and healthy response (反应) to a frightening event. But when fear runs unchecked, a person may make dangerous choices. It takes practice to learn to stay calm in frightening situations, but it can be done.

7 . Tropical (热带的) forests could become so hot that some kinds of leaves will no longer be able to conduct photosynthesis (光 合 作用), according to a study. The photosynthetic machinery in tropical trees begins to fail at about 46.7℃ on average. The research suggests that forests may be nearing dangerous temperature sooner than expected. Models predict that once we hit a global temperature increase of 3.9℃, these forests might experience mass leaf damage.

Chris Doughty, an associate professor at Northern Arizona University and the lead researcher of the study, said the leaf-warming experiments had revealed a nonlinear rise in temperatures. “We were really surprised that when we warmed leaves by 2, 3 or 4℃, the highest leaf temperatures actually increased by 8℃. This shows a concerning nonlinear feedback that we were not expecting.” said Doughty. “If we adopt a do-nothing response to climate change and tropical forest air temperatures increase by greater than 4℃, there could be massive leaf death.” he added.

Avoiding high emissions (排放) in the first place is key to stabilizing temperatures. “We should do all we can to avoid high-emissions. Under low-emissions, almost all tropical forest tree leaves can avoid death from overheating and the trees will survive,” said Simon Lewis, a professor of global change science at University College London. “Yet what the study doesn’t look at is heatwaves. We still might see tree deaths from overheating for limited periods during heatwaves under lower emissions.”

Researchers suggest that the damage is not yet unchanged. “Vote for people who are serious about addressing climate change and transferring to low-carbon economies, ”Disney, one researcher, advocated. More generally, we can all recognize the importance of supporting those countries and people who live in and rely on tropical forests economically, But the serious changes to tropical forests don’t just affect the local people it’s a global issue.

8 . Many disaster-relief programs transport tons of supplies, such as food, water and heavy equipment, by road using large trucks. But some supplies may weigh just a few kilograms or less. For example, a package might contain a few doses of life-saving medicine.

The parachutes (降落伞) that carry these packages from planes are often made of nylon (尼龙). After one use, these parachutes are usually discarded. Because nylon is a polymer (聚合物), it does not decompose quickly. Therefore, Natalie looked for a greener alternative.

Nylon is strong, but a parachute used only once for light packages does not need to be that strong. Paper might be good enough, thought the teen. Plus, a paper parachute can be folded into a tiny package, just like a fabric parachute. Moreover, she notes there are many different ways to fold the unopened paper parachute.

Natalie came up with several folded designs and tested them. Her first models were small, so she could test them indoors. Two were triangular (三角形的). Two more were rectangular (长方形的). One of the rectangular ones opened most smoothly, she found. It also fell and landed most steadily as it dropped through the air. “Such features can be important when the goal is to deliver a package to the ground softly and accurately,” she says.

Natalie showcased her designs at the Intel International Science and Engineering Fair. Natalie’s single-use paper parachutes are not harmful to the environment. They are also less expensive than parachutes made from more traditional materials. A nylon parachute of the same size as her design would cost about $31, she says. One made from silk, another common parachute fabric, would cost almost $16. But a parachute made from paper would likely cost less than $1, Natalie estimates.