The word "incorporate" in the passage is closest in meaning toA．describeB．includeC．expandD

world?

A．In mid-latitude regions

B．In tropical areas

C．In mid-continental regions

D．At the poles

, and biological components of Earths climate system in order to make accurate predictions of the effects the rise in greenhouse gases will have on future global climates. Global circulation models are important tools in this process. These models incorporate current knowledge on atmospheric circulation patterns, ocean currents, the effect of landmasses, and the like to predict climate under changed conditions. There are several models, and all show agreement on a global scale. For example, all models show substantial changes in climate when carbon dioxide concentration is doubled. However, there are significant differences in the regional climates predicted by different models. Most models project greater temperature increases in mid-latitude regions and in mid-continental regions relative to the global average. Additionally, changes in precipitation patterns are predicted, with decreases in mid-latitude regions and increased rainfall in some tropical areas. Finally, most models predict that there will be increased occurrences of extreme events, such as extended periods without rain(drought), extreme heat waves, greater seasonal variation in temperatures, and increases in the frequency and magnitude of severe storms. Plants and animals have strong responses to virtually every aspect of these projected global changes.

The phrase "this process" refers to

A．the interaction between physical and biological components of Earth"s climate system

B．the increase of greenhouse gases in the atmosphere

C．predicting future global climate

D．global circulation models

The word "consensus" in the passage is closest in meaning to

A．publication

B．debate

C．collection

D．agreement

on. Human activities are having a major influence on atmospheric carbon dioxide concentrations, which are rising so fast that current predictions are that atmospheric concentrations of carbon dioxide will double in the next 50 to 100 years. The Intergovernmental Panel on Climate Change(IPCC)report in 1992, which represents a consensus of most atmospheric scientists, predicts that a doubling of carbon dioxide concentration would raise global temperatures anywhere between 1.4°C and 4.5°C. The IPCC report issued in 2001 raised the temperature prediction almost twofold. The suggested rise in temperature is greater than the changes that occurred in the past between ice ages. The increase in temperatures would not be uniform, with the smallest changes at the equator and changes two or three times as great at the poles. The local effects of these global changes are difficult to predict, but it is generally agreed that they may include alterations in ocean currents, increased winter flooding in some areas of the Northern Hemisphere, a higher incidence of summer drought in some areas, and rising sea levels, which may flood low-lying countries.

According to paragraph 2, what can be said about the effects of global changes?

A．The local plants and animals will be permanently damaged.

B．It is hard to know exactly what form. the local effects will take.

C．Seawater levels will fall around the world.

D．The effects will not occur in some regions of the world.

hey

A．absorb 70 percent of the Sun"s energy

B．can be rapidly replenished in the atmosphere

C．remove pollutants from ecosystems

D．help keep Earth warm

Listen to Track 52.

A．To correct a misstatement he made about the Sahara"s climate

B．To suggest that the current dryness of the Sahara is exaggerated

C．To indicate that scientists are not in agreement about the Sahara"s past climate

D．To emphasize the difference between the current and past climates of the Sahara

e development of the Egyptian civilization. Which sentence best describes the professors attitude toward this theory?

A．It is exciting because it perfectly explains recent archaeological discoveries.

B．It is problematic because it goes too far beyond the generally available data.

C．It raises an interesting possibility and he hopes to see more evidence for it.

D．It cannot be taken seriously until it explains how the migrants got to Egypt.

ert?

A．The prevailing winds became stronger.

B．The seasonal rains moved to a different area.

C．The vegetation started to die off in large areas.

D．The soil lost its ability to retain rainwater.

about past climate changes? Choose 2 answers.

A．That some climate changes benefitted the development of civilization

B．That some climate changes were not caused by human activity

C．That some climate changes were caused by a decrease of moisture in the atmosphere

D．That some climate changes were caused by changes in Earth"s motion and position

to support this? Choose 3 answers.

A．Ancient pollen

B．Bones from large animals

C．Rock paintings

D．Agriculture in ancient Egypt

E．Underground water