假定你是李华，你校将举办外国学生中文演讲比赛，请给你的英国朋友George写封邮...

阅读下面材料,在空白处填入适当的内容(1个单词)或括号内单词的正确形式。

Something significant is happening to the world population-it is aging. The median(中位数的)age of an American in 19501.(be)30-today it is 41 and is expected2.(increase)to 42 by 2050. For Japan, the3.(number)are more striking-22 in 1950, 46 today and 53 in 2050. In 2015, one in 12 people around the world were over 65；by 2050, it will be one in six.

This aging of the population is driven4.two factors. The first is declining birthrates, which means old generations are large5.(compare)to younger generations, and so, on average, the population becomes6.(old)than before. This is7.(particular)true in the US. The second reason is that people are living longer. A child born in the US today has8.very realistic chance of living beyond 100 and needs to plan accordingly.

People tend to focus on the first factor. However, greater attention should9.(place)on longevity(长寿). It isn't just that people are, on average, living longer. It's also that they are on average healthier10.more productive for longer. Therefore, they can work for longer, consume more and in general be a boost to the economy.

    I was born legally blind. Of all the stories of my early childhood，the one about a______is my mother's favorite.

I was only two when the______occurred. We had just arrived home from a trip. Mom lifted me out of the car and _____to speak to the driver. I took advantage of my brief______to dash across the lawn(草坪)-and hit a large maple tree！I was running so fast that I bounced off the trunk and______on my backside. Mom______me to start crying，but I just sat there for a minute. Then I______myself up and kept right on going. Mom always______here that，as many times as I______across the lawn after that，I never again______into that tree.

Mom loves to use this story as an______. It reminds her that children don't enter life______to take risks or unwilling to______again when they fall down. She never wanted me to lose that______as I grew older. When I______my major life decisions，I was still that little girl tearing full-speed across the lawn. I studied abroad and later moved away from my parents' home to look for a______, Through years of______, I have become a respected teacher in a school serving high-need students.

We are almost certain to get______at some point during the process of achieving our goal. When that happens，don't sit in the grass and______.Just get up and keep on going It will all be worth it______.

1.A.trip B.race C.tree D.driver

2.A.incident B.change C.illness D.problem

3.A.feared B.refused C.forgot D.turned

4.A.delay B.absence C.freedom D.rest

5.A.landed B.slept C.laughed D.wept

6.A.promised B.encouraged C.allowed D.expected

7.A.woke B.picked C.warmed D.gave

8.A.adds B.replies C.admits D.supposes

9.A.drove B.lived C.stood D.zoomed

10.A.crashed B.broke C.climbed D.looked

11.A.answer B.example C.excuse D.order

12.A.able B.ashamed C.afraid D.anxious

13.A.ask B.share C.learn D.try

14.A.honesty B.toughness C.kindness D.curiosity

15.A.regretted B.reviewed C.made D.explained

16.A.job B.friend C.fortune D.house

17.A.memories B.efforts C.research D.experience

18.A.mixed up B.fed up C.knocked down D.settled down

19.A.play B.relax C.dream D.cry

20.A.all at once B.in the end C.in either case D.as a result

    Let's take a minute to think about the water we use. The human body is 60% water and we need to drink lots of water to be healthy. When we are thirsty we just go to the kitchen and fill a glass with clean water.

1.For example, farmers, who produce the food we eat, use water to make the plants grow. When we turn on a light or switch on a TV or a computer we use energy and we need water to produce this energy.

The truth is that we are lucky enough to have clean water whenever we want，but this is not the case for many people around the world.2.That's around one in 10 people in the world. If we drink dirty water，we can catch diseases from the bacteria and become ill. Every year over 500，000 children die from diarrhea(腹泻)from dirty water. That's around 1，400 children every day！Also，in some countries children walk many kilometres every day to get water.3.Therefore，they don't have time to learn how to read or write and don't get an education.

4.On this day every year，countries around the world hold events to educate people about the problems of dirty water and that clean water is something that everyone should have around the world. At one school in the UK，children between the ages of 10 and 15 walk 6km with six litres of water.5.People give them money to do this and all the money helps get clean water to as many people as possible around the world.

A. We use water indirectly too.

B. Every system in our body depends on water to function.

C. It is to inspire people to learn more about water-related problems

D. If children walk many hours a day to get water，they can't go to school.

E. Did you know that around 750 million people do not have clean water to drink？

F. In 1993 the United Nations decided that March 22nd is the World Day for Water.

G. In this way，they know how it feels to walk a long distance carrying heavy bottles.

    Today's world is not an easy adjustment for young adults. Key skill set for success is persistence (毅力), a characteristic that researchers say is heavily influenced by fathers. Researchers from Brigham Young University discovered that fathers are in a unique position to help their adolescent children learn persistence.

BYU professors Laura Padilla-Walker and Randal Day arrived at these findings after following 325 American families over several years. And over time，the persistence gained through fathers led to higher achievement in school.

"There are relatively few studies that stress the unique role of fathers，"Padilla-Walker said. "This research also helps to prove that characteristics such as persistence-which can be taught-are key to a child's life success.”

Researchers determined that dads need to practice an "authoritative" parenting style. Authoritative parenting is not authoritarian:rigid，demanding or controlling. Rather，an authoritative parenting style includes some of the following characteristics:children feel warmth and love from their father；responsibility and the reasons behind rules are stressed children are given an appropriate level of autonomy(自主权).

In the study，about 52 percent of the dads exhibited above-average levels of authoritative parenting. A key finding is that over time，children raised by an authoritative father were significantly more likely to develop persistence，which leads to better outcomes in school.

This particular study examined 11 to 14-year-olds living in two-parent homes. Yet the researchers suggest that single parents still may play a role in teaching the benefits of persistence，which is an avenue of future research.

1.What is special about the BYU professors' study?

A.It centered on fathers' role in parenting.

B.It was based on a number of large families.

C.It analyzed different kinds of parenting styles.

D.It aimed to improve kids' achievement in school.

2.What would an authoritative father do when raising his children?

A.Ignore their demands. B.Make decisions for them.

C.Control their behaviors. D.Explain the rules to them.

3.Which group can be a focus of future studies according to the researchers?

A.Single parents.

B.Children aged from 11 to 14.

C.Authoritarian fathers.

D.Mothers in two-parent homes.

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

A.Three Characteristics of Authoritative Fathers.

B.Key Skills for Young Adults to Succeed in Future.

C.Children Tend to Learn Determination from Father.

D.Family Relationship Influences School Performance.

    Milwaukee, Wisconsin, is road testing a new way to keep winter roads ice-free – by spreading on them cheese brine, the salty liquid used to make soft cheese, like mozzarella.

Wisconsin, also called "America's Dairyland," is famous for its cheese. The state produced 2.8 billion pounds of cheese last year! a result, there was a lot of leftover cheese brine. Disposing of(处置)the brine can be expensive. So what should cheese makers do with the waste?

Normally, towns use rock salt to de-ice streets. The salt lowers waters' freezing point, causing ice to melt(融化). But using cheese brine could help both cheese producers and cities save money, while keeping roads safe. Cheese brine has salt in it, which, like the rock salt, helps lower water's freezing point.

In addition to saving money, cheese brine could also be a more environment-friendly option. Many people suspect that all the rock salt used every winter is harming the environment.

Rock salt is made of sodium chloride, the sane con-pound (化合物)in ordinary table salt. Sounds harmless, right? But while you probably add only a small amount of salt to your food, road crews spread about 20 million tons of salt on U.S. Roads every year!

The chemical washes off roads and goes into the ground. There it can pollute drinking water, harm plants. and eat away soil. By spreading cheese brine on streets before adding a layer of rock salt, Milwaukee may be able to cut its rock salt use by 30 percent.

Cheese brine has a downside too – a shell similar to that of bad milk. "I don't really mind it," Emil Norby told Modern Farmer magazine. He works for one of Wisconsin's county highway commissions and came up with the idea of using cheese brine. "Our roads smell like Wisconsin!" he said.

1.Why can cheese brine help keep winter roads ice-free?

A.It is soft. B.It contains salt. C.It is warm. D.It has milk in it.

2.What is a benefit of using cheese urine on roads?

A.Improving air quality. B.Increasing sales of rock salt.

C.Reducing water pollution. D.Saving the cheese industry.

3.Milwaukee's new way to de-ice streets may be an example of_______________.

A.barking up the wrong tree B.putting the cart before the horse

C.robbing Peter to pay Paul D.killing two birds with one stone