【推荐2】Have you ever spent an afternoon in the backyard, maybe grilling or enjoying a basketball game, when suddenly you notice that everything goes quiet? There is an old phrase “calm before the storm”， often used in a situation—a quiet period just before a great activity or excitement. According to our own experience, we know there is actually calm before the storm. But what causes this calm? And is it always calm before the storm? Let's hear what scientists have to say.

A period of calm happens in a particular kind of storm, the simplest kind of storm—a single－cell thunderstorm. In this type of thunderstorm, there is usually only one main updraft, which is warm, damp air and drawn from places near the ground. Storms need warm and damp air as fuel, so they typically draw that air in from surrounding environment. Storms can draw in the air that fit their need from all directions—even from the direction in which the storm is traveling.

As the warm, damp air is pulled into a storm system, it leaves a low－pressure vacuum(真空) coming after. The rising air meets the cold dry air that has already existed in the storm clouds, thus the temperature of the warm, damp air drops, and the water vapour(水蒸气) in it changes into tiny drops that are a precondition of rain. These drops accumulate and build on larger particles like dust, until they grow large enough to form raindrops.

This warm, damp air keeps moving upwards, but it becomes cooler and drier during its trip through cloud. When it reaches the top of the cloud, the air gets spit out(被挤出) at the top. This air is sent rolling out over the big thunderclouds. From there, the air goes down. Warm and dry air is relatively stable, and once it covers a region, that air, in turn, causes the calm before a storm.

Most thunderstorms, though, don't start with calm. That's because most are actually groups of storms with complex wind patterns. There's so much air moving up and down storm groups that the calm before the storm never happens. Instead, before the storm, it might be really windy!

1. Which best fits the description of a particular kind of storm?

A．A storm with air drawn from every direction.

B．A thunderstorm without strong winds.

C．A thunderstorm with a single shape.

D．A storm fueled by moving air from the ground.

2. What does the underlined word “it” in Paragraph 3 refer to?

A．Cold and dry air.	B．Warm and damp air.
C．Cold and damp air.	D．Warm and dry air.

3. Which does the writer most likely agree to?

A．Presence of the calm relies on stable air.

B．Storm happens without air moving up and down.

C．The drier the air is, the bigger the storm will be.

D．Not all thunderstorms start with the calm.

4. What is the passage mainly about?

A．Causes and effects of a heavy storm.

B．An explanation of the calm before a storm.

C．A personal experience of a heavy storm.

D．A brief description of a peaceful storm.

【推荐3】Yellowstone Weather

Yellowstone National Park is at high altitude. Most of the park is above 7500 feet (2275 meters).

Yellowstone’s weather is unpredictable. In summer, it may be warm and sunny with temperatures in the high 70s. At night in any given month, the temperature may drop close to freezing. So it is best to come prepared for cold evenings and mornings, especially if you are camping or hiking. When you leave your campsite, please leave it prepared for possible thundershowers and wind.

A sunny warm day may become fiercely stormy with wind, rain, sleet and sometimes snow. Without enough clothing, an easy day hike or boat trip can turn into a battle for survival.

Seasonal Weather Information

Spring

Cold and snow continue into May, although temperatures gradually climb. Early in spring, daytime temperatures average in the 40s to 50s; by late May and June, they may reach the 60s and 70s. Nighttime lows fall below freezing.            

Summer

Daytime temperatures are usually in the 70s, occasionally reaching the 80s in the lower area. Nights are cool, temperatures may drop in the 40s and 30s, sometimes even the 20s. June can be cool and rainy; July and August tend to be somewhat drier, although afternoon thundershowers are common.

Fall

Weather can be pleasant, although temperatures average 10~20 degrees lower than summer readings. Nighttime lows can fall into the teens and even lower. Snowstorms increase in frequency as the weeks go by or towards the end of the fall season.

Winter

Temperatures often stay near zero throughout the day, occasionally reaching high in the 20s. Subzero nighttime lows are common. Annual snowfall averages nearly 150 inches in most of the park. At higher places, 200~400 inches of snow have been recorded.

1. The theme (主题) of this passage is   ____ in Yellowstone National Park.

A．the special weather	B．the beautiful scenery
C．campsites for free	D．terrible thunderstorms

2. This passage is mainly written for those who plan to ____in Yellowstone National Park.

A．do research work	B．take a business trip
C．have sports games	D．spend their holidays or take a tour

3. Which of the following best describes Yellowstone’s weather?

A．The weather is generally changeable and it snows most of the year.

B．The lowest nighttime temperature often stays about zero in winter.

C．Weather in fall is pleasant and temperatures never fall below freezing.

D．It’s pretty warm in the day and very cold at night throughout the year.

4. If you are planning to spend your holiday in Yellowstone National Park in summer, what should you take with you?

A．Just some light clothing such as T-shirts or skirts.

B．Just some warm clothing such as sweaters or coats.

C．Both light clothing and warm clothing.

D．Either light clothing or warm clothing.

【推荐2】ROME— four people, including the wife of the factory's owner, died on Wednesday after explosions （爆炸）at the Barcelona Pozzo di Gotto fireworks company, Italian media reported.

According to online reports by La Republic and TGCOM24, at least one other person is missing and three others are seriously injured, with two of them in dangerous condition. Among the dead was 71-year-old Venera Mazzeo, the wife of the factory owner Vito Costa. Mazzeo reportedly died on the scene. Antonio Costa, the owner's son, was seriously injured and was transported to a hospital in the regional capital of Palermo for treatment. Less seriously injured persons were moved to the nearby Milazzo Hospital to be treated for burns and other injuries. Many were transported by local people who reached the scene before ambulances could arrive, reports said.

The factory, located near the northeast of the southern Italian island of Sicily, near the city of Messina, has been in operation for more than ten years without any accident. Police reports showed that two separate explosions took place, with the first explosion likely causing the second one. Media reports said that police have guessed that sparks （火花）from a repairing project reached some of the explosive material stored in the factory and was likely the cause of the first explosion.

Reports also showed that firefighters were able to control the flame, which burnt buildings on the factory and threatened nearby structures.

1. How many people lost their lives in the accident except Venera Mazzeo?

A．Three.	B．Four.
C．Five.	D．Six.

2. What probably caused the first explosion according to the passage?

A．One worker's cigarette spark.

B．A fire nearby the factory.

C．The explosive material in the factory.

D．The sparks from a repairing project.

3. What can we infer from the passage?

A．Antonio Costa died on the scene because of the flame.

B．Most injured persons were sent to hospital by ambulance.

C．The factory had been in safe operation before the explosions.

D．There were three explosions in total in the accident.

4. Where does the passage probably come from?

A．A travel guide.	B．A newspaper.
C．A magazine.	D．A science report.

【推荐3】An artist in Oakland, California is using his skills to help the homeless. Greg Kloehn builds very small shelters that make life on the streets a little more comfortable. The structures offer the homeless some safety and protection from bad weather. Each little house also has wheels on the bottom so it can go wherever its owner goes.

Greg Kloehn has given away at least 20 tiny houses. Several are on the roadside near an active railroad. On a recent day, Mr.Kloehn stops at one to visit Oscar Young. The two men hug. Inside his little shelter Mr.Young gets relief from cold nights on the streets. Mr.Kloehn also visits Sweet­Pea, another friend who also lives in one of the little homes the artist built. She says it keeps her safe and protects her belongings.

In the mornings, Mr. Kloehn searches the streets for building materials. He gathers what he can and takes it to his studio. There, he puts the houses together. Empty coffee bags become roof material. A washing machine door and refrigerator part become windows. Nails,screws and the sticky glue hold all the pieces together. The artist also attaches a small electrical device to the house. The device is powered by the sun.

Some of the people living on the streets once had normal houses of their own. But some of the people say they have learned to live with less and they are thankful to that man.

Mr.Kloehn says his work is not a social project. He says he is just someone using his skills to help his homeless neighbors.

1. The following are the advantages of the small shelters EXCEPT ________.

A．saving power and energy

B．protecting possessions of the homeless

C．decorating the streets where they are

D．keeping the homeless safe and comfortable

2. We can learn from the passage that ________.

A．Greg Kloehn has sold at least 20 tiny houses

B．an act of kindness has made people simple and grateful

C．the shelters are immovable

D．the government has got involved in the action

3. The passage is likely taken from ________.

A．an official report

B．an art review

C．a science magazine

D．a news report

4. What’s the main idea of the passage?

A．An artist creates homes for the homeless.

B．A more comfortable shelter on the streets.

C．A successful social project in Oakland.

D．An artist makes a living by designing small shelters.