When I was growing up, I had an old neighbor named Doctor Gibbs. He didn't look like any doctor I'd ever known. He never yelled at us for playing in his yard, but was always very kind.

    When Doctor Gibbs wasn't saving lives, he was planting trees. He had some interesting theories about planting trees. He believed in the principle “No pain, no gain”. He hardly watered his new trees, which flew in the face of conventional(传统的) wisdom. Once I asked why and he told me that watering plants spoiled them because it made them grow weaker. He said you had to make things tough for the trees so that only the strongest could survive. He talked about how watering trees made them develop shallow roots and how, if they were not watered, trees would grow deep roots in search of water. So, instead of watering his trees every morning, he'd beat them with a rolled-up newspaper. I asked him why he did that, and he said it was to get the tree's attention.

    Doctor Gibbs died a couple of years after I left home. Every now and then, I walked by his house and looked at the trees that I'd watched him plant some twenty five years ago. They were all tall and strong.

    I planted a couple of trees myself a few years ago. Two years of attending these trees meant they grew up weak. Whenever a cold wind blew, their branches trembled. Adversity(逆境) seemed to benefit Doctor Gibb's trees in ways comfort and ease never could.

    Every night before I go to bed, I check on my two sons. I often pray that their lives will be easy. But lately I've been thinking that it's time to change my prayer. I know my children are going to meet with hardship. There's always a cold wind blowing somewhere. What we need to do is to pray for deep roots, so when the rains fall and the winds blow, we won't be torn apart.

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    Here's a selection of festivals for tourists to the United States in summer.

    San Francisco Silent Film Festival

    Films at this odd cinematic event have a variety of musical accompaniments,including piano and violin.It includes some classic silent movies.If you want to see them all,you can buy a festival pass.

    May 29 to June 1; www.silentfilm.org

    Union Street Festival

    This popular street fair stretches out over six blocks of the city,in the fashionable shopping area of Union Street.This year,there's beer,wine tasting and more separate themes—fashion,cuisine,tech,local,craft,and health and fitness.

    June 7 to 10; www.unionstreefestival.com 

    North Beach Festival

    This is San Francisco's oldest street party,with live entertainment,delicious food and arts and crafts.Situated in the Little Italy district,known for its associations with the "Beat Generation",festival goers are guaranteed plenty of good Italian food.There is also as the “blessing of the animals”,a San Francisco tradition which takes place at the National Shrine of Saint Francis of Assisi (610 Vallejo Street) at 2 pm on both days of the festival.

    June 14 to 16; www.sfnorthbeach.org

    Stern Grove Festival

    This is the oldest free summer arts festival of its kind in the United States.It includes a wide variety of acts,from the local symphony orchestra to well known artists such as Smokey Robinson.

    Sundays from June 22 to Aug 24; www.sterngrove.org

    Scientists have always been interested in the high level of organization in ant societies. American researchers have watched ants build life-saving rafts to keep afloat during floods. They also have recorded how ants choose their next queen — the female whose job is to produce eggs.

    New technology is helping to improve researchers' understanding of the insects. But there is still a lot to be learned.

    Fire ants living in Brazilian forests are perfectly at home in an environment where flooding is common. To save themselves, the insects connect their legs together and create floating rafts. Some ant rafts can be up to 20 centimeters wide.

    David Hu is an engineer with the Georgia Institute of Technology, also known as Georgia Tech, saying, "If you have 100 ants, which means 600 legs, 99 percent of those legs will be connected to a neighbor. So they're very, very good at keeping this network. "

    David Hu and other Georgia Tech researchers wanted to study ants and the secret of their engineering. They froze ant rafts and then looked at them with the help of computed technology, or CT images. The pictures showed that larger ants serve in central positions to which smaller ants hold. The larger ants create pockets of air that keep the insects afloat.

    Scientists say small robots or materials that can change shape could be programmed in a similar way, working towards a shared goal.

    Researchers at North Carolina State University are also studying ants. They examined how Indian jumping ants choose the leader of the colony when they lose their top female or queen.

    Calorie(卡路里)counts are everywhere. They appear on restaurant menus, milk boxes and bags of baby carrots. Grocery stores display lots of foods packaged with bright and colorful “low-calorie” claims.

A calorie is the measure of stored energy in something—energy that can be released as heat when burned. The term calorie on food labels is short for kilocalorie. A kilocalorie is the amount of energy it takes to raise the temperature of one kilogram of water by 1 degree Celsius. But what does boiling water have to do with your body's release of energy from food? After all, your body doesn't start boiling after eating. It does, however, chemically break down food into sugars. The body then releases the energy to fuel processes and activities throughout each hour of the day.

    Food contains three main types of nutrients that deliver energy: fats, proteins and carbs(碳水化合物). A process called metabolism(新陈代谢) first cuts these into small pieces; Proteins break down into amino acids(氨基酸), fats into fatty acids and carbs into simple sugars. Then, the body uses oxygen to break down these materials to release heat.

Most of this energy goes toward powering the heart, lungs, brain and other vital processes. Exercise and other activities also use energy. If energy-rich nutrients aren't used right away, your body will hoard them—first in the liver(肝脏), and then later as body fat.

    In general, someone should eat the same amount of energy each day as his or her body will use. If the balance is off, they will win lose or gain weight. It's very easy to eat more calories than the body needs. Having two 200-calorie donuts in addition to regular meals could easily put teens over their daily needs. At the same time, it's nearly impossible to balance overeating with extra exercise. Running a mile burns just 100 calories. Knowing how many calories are in the food we eat can help keep the energy in and out balanced.

    Do you worry about entering senior high school? Everything, from study to environment, has changed. Can you adapt yourself to it?

    You're not alone. Remember that everybody else in your year is in the same boat. You may not notice it, but they're just as nervous as you are.

    Moving to senior high school is a chance, not a problem. Things are different, and all you need to do is to be polite and learn the new rules.

    The teachers will help. If you don't know what to do or are worried about something, then ask for help. Teachers are probably the best people to turn to, because they have experience in helping new students. Pay attention to what your teachers say.

    Everything changes. There are lots of differences between junior high school and senior high school. You will have your lessons with different teachers in different rooms. You will have homework for different subjects on different days, so make sure you get organized. Make sure you know which rooms your classes are in and which days you have your different subjects on.

Other points:

    If you've got an older brother or sister at the school, then ask them for advice.

    Be yourself! It sounds simple, but things will become better if you just act naturally.

    Having early nights makes a difference. You'll also find it easier to get up in the morning!

Help Hermit Crabs

    Hermit crabs are nature's recyclers. They eat waste and help keep oceans and shores clean. Unlike other crabs, the hermit crab has a thin outer shell over its soft tail. This makes the hermit crab easy prey for hungry predators(天敌).Hermit crabs stay safe by living in old seashells. A hermit crab is picky(狡猾); it tries on many shells until it finds one that fits just right. In recent years, however, many hermit crabs have had trouble finding their perfect homes. What is the problems. There are not enough shells to go around!

    One reason for the seashell shortage is that ocean water is not as clean as it once was. This has caused chemical changes to sea water. Some sea animals, like snails, are affected by these changes.  Now there are fewer snails making shells. People visiting the beach often take shells home as souvenirs(纪念品).This is another problem. Other people even take shells for their own pet hermit crabs! They do not realize that hermit crabs in the wild need those shells too.

    Now people are working to solve this hermit crab housing shortage. They are teaching beach-Boers to leave seashells where they belong--at the seashore! Some people even make fake seashells that they hope the hermit crabs will like. For example, a group called Project Shelter invited people who visited their website to create different designs for hermit crab shells.

    These designers had a lot to consider. What kind of material should be used to build a seashells. The material must be light enough for the hermit crab to carry, but strong enough to protect the crab from predators. The man-made shells could not contain glue or any other substance(物质)that might harm a hermit crab. Another challenge with building a hermit crab home was the opening to the shell. Too big would mean the crab would not feel safe. Too small would be uncomfortable, and the crab would not want to move in.

    The Project Shelter shells are placed in the wild for hermit crabs to find. Lucky hermit crabs can move into these new dream homes.