2. Cirrus Clouds

Because high-altitude winds pull cirrus clouds apart, these

wispy clouds often look like spider webs. Cirrus clouds

often mean warm weather; however, they are the coldest

clouds. Because they often rise to heights of 40,000 feet, the

moisture contained in cirrus clouds is frozen into ice

crystals.

3. Clouds and Oceans

Because the land and the sea affect clouds differently,

sailors often use clouds to help navigate. Clouds will often

form over land; the skies out at sea, on the contrary, will

remain cloudless. Early Polynesian navigators did not have

compasses; nevertheless, they could sail from island to

Island by reading the clouds.

Exercise 37:

Complete the following sentences, using ideas about

your area or country. Then, give any additional information you

may know on the topic.

Examples: The United States has a Clean Water Act that

should. . . .

The United States has a Clean Water Act that should

control or prevent pollution.

Despite.. . .

Despite this law, many companies pollute.

1. My government has many programs to help....

In spite o f . . . .

2. We have laws to protect....

Despite....

3. We also have laws against....

However,....

4. The most important resources in my area (country) are....

In spite o f . . . .

5. Farmers in my area (country) produce....

However,....

6. Our major energy sources are....

7. We don't produce enough....

In spite o f . . . .

8. Politicians in my area (country) are not supposed to....

Nevertheless,....

Exercise 38:

Read the following pairs of sentences and decide

whether the information shows concession or opposition. Then

combine the sentences with while, where, whereas, although, even

though, or though. Be sure to change or omit words and to add

punctuation when necessary.

Example: Each year, 80,000 cubic miles of water evaporate from

the oceans. Fifteen thousand cubic miles of water

evaporate from land, (opposition)

Each year, while 80,000 cubic miles of water evaporate

from the oceans, 15,000 evaporate from land.

1. Land contributes less than 15 percent of the water vapor in the

atmosphere. Land receives over one-quarter of the world's

annual rainfall (approximately 24,000 cubic miles).

2. The actual locations of rainfall depend on geography and winds.

The total annual rainfall in the world is enough to provide every

human an average of 22,000 gallons every day.

3. Every year, 470 inches of rain fall on Mt. Waialeale in Hawaii.

Desert regions in Africa get less than 1 inch of rain annually.

4. Each year, 1.7 inches of rain fall in California's Death Valley.

A few hundred miles away, in the Pacific Northwest, 140 to 150

inches of rain fall.

5. All precipitation begins with the cooling and condensing of

water vapor. It may reach earth as rain, sleet, snow, or hail,

depending on air currents, temperature, and humidity.

6. In clean air, only temperature and humidity determine when

vapor condenses into water. In polluted air, chemicals and

particles of dust affect the process.

7. In clear air, condensation happens slowly. In particle-filled air,

condensation occurs much more rapidly.

8. Meteorologists do not know all the effects of air pollution. Many

believe that pollution can and will change our weather patterns.

Now, rewrite your sentences from the preceding exercise with the

transitions however, nevertheless, on the contrary, or on the other

hand.

Exercise 39:

Combine the following sentences, using although,

even though, however, nevertheless, while, where, on the other hand,

or on the contrary.

Example: Water exists in three forms—gas, liquid, and solid. The

most common freshwater form on earth is ice.

Although water exists in three forms—gas, liquid, and

solid—the most common freshwater form on earth is

ice.

1. Almost three-quarters of the earth's surface is water. We cannot

easily use most of this water.

2. Seventy-one percent of the earth's surface is covered by

saltwater ocean. Seventy-five percent of all the world's fresh

water is in glacial ice.

3. Water freezes at 32 degrees Fahrenheit (O degrees Celsius). Snow

and ice depend on other factors that influence temperature,

such as altitude.

4. Land masses in the Northern Hemisphere are large enough to

influence and even create climates. Land masses in the Southern

Hemisphere are too small and too far from the South Pole

to create cold climates.

5. The Arctic is a frozen ocean, covered by sea ice and surrounded

by land. The Antarctic is a frozen continent, covered by glacier

ice and completely surrounded by sea.

6. Snow and ice cover the peaks of many mountains. The regional

"snow line" varies greatly according to latitude.

7. Near the poles, the snow line is at sea level. In the tropics, the

snow line is above 20,000 feet (6,000 meters).

8. Glaciers can exist on moderately high mountains in the middle

latitudes. Near the equator, glaciers exist on only the highest

peaks, such as Chimborazo, Kilimanjaro, and Mount Kenya.

On Your Own After you have finished combining these

sentences, use them to write a paragraph on snow and ice. You

may want to rewrite, add, or omit portions in order to vary your

sentences.

Activity In pairs or in small groups, use the following to learn

how to read a weather map. Check the weather map in your local

newspaper and prepare a short forecast of upcoming weather. Tell

what you are basing your predictions on, using as many connectors

of cause, purpose, or contrast as you can.

Exercise 40:

Rephrase the following sentences, changing clauses

of opposition to clauses of comparison. Give at least two new

versions for each.

Example: Mt. Waialeale, Hawaii, gets 460 inches of rain annually,

while the Atacama Desert in Chile gets almost no rain.

Mt. Waialeale gets much more rain than the Atacama

Desert in Chile does.

The Atacama Desert gets much less rain than Mt.

Waialeale does.

The Atacama Desert is much drier than Mt. Waialeale

is.

Mt. Waialeale is much wetter (rainier) than the Atacama

Desert is.

1. Portland, Oregon, is almost always cloudy, while Los Angeles,

California, is almost always sunny.

2. Parts of upstate New York received fifteen feet of snow in 1978,

while almost no snow fell in Wisconsin that winter.

3. Parts of Libya can reach 130 degrees Fahrenheit, while parts

of the polar areas never get above O degrees.

4. Mount Washington in New Hampshire has winds of over one

hundred miles per hour, while areas around the equator almost

never have winds.

Activity Give a brief description of the climate in your home

town, including information about temperature, wind, rain, snow,

clouds, and pollution. Then compare it to the city where you are

living now or to another city or area that you particularly like.

Exercise 41:

Combine the following sentences with so that.

Change or omit words when necessary.

Example: In parts of the world, rainfall is sparse. People in those

areas constantly conserve water.