Bài ôn tập tổng hợp 1

REVISION
Acid Dust
Calcite-containing dust particles blow into the air and combine with nitric acid in polluted air from factories to form an entirely new particle-calcium nitrate. These nitrates have optical and chemical properties that are completely different from those of the originally dry dust particles. Due to this, climate models need to be updated to reflect this chemistry. Calcite dust is common in arid areas such as Israel, where this past winter scientists collected particles for analysis.
Working from a mountaintop, the team collected dust that had blown in from the northern shores of Egypt, Sinai, and southern Israel. The particles had combined with air containing pollutants that came from Cairo. They analyzed nearly 2,000 individual particles and observed the physical and chemical changes at the W.R. Wiley Environmental Molecular Sciences Laboratory.
An important change in the properties of the newly formed nitrate particles is that they absorb water and retain moisture. These wet particles can scatter and absorb sunlight-presenting climate modelers, who need to know where the energy is going, a new wild card to deal with. Other studies of dust samples from Sahara and Saudi Arabia coast and loess from China show that the higher the calcium in the mineral, the more reactive they are with nitric acid. In fact, once the particles is changed, it stays that way.

Discuss on:
What is the main idea of the passage? – Climate models have to be updated because of the new particles calcium nitrate.
Why do climate models need to be updated to reflect the chemistry of calcium nitrate?
The new particles can absorb water and retain moisture
The new particles can scatter and absorb sunlight
To stop acid dust
Both A and B
Do the articles react with nitric acid?
No, but they continue to absorb the sun’s energy
No, and the particles do not change
Yes, but the changes are temporary
Yes, but the changes are permanent
which of the following may be result of these particles?
The chance of an ice age is increased
We may be see more rainbows
The greenhouse effects are increased
We may be see an increase in carbon dioxide
Why does the passage begin with a description of the properties of calcium nitrate?
To give background information so the reader can understand the topic better
Because calcium nitrate is the main idea
To show how elements combine to create calcium nitrate
To prove the existence of calcium nitrate
The word “those” in paragraph 1 refer to:
nitrates
properties
particles
models
In the scientists’ research, where did the pollutants come from originally?
arid areas
the Saudi Coast
Cairo
The Sahara Desert
It can be inferred that “retain” in paragraph 3 is closest in meaning to:
hold
lose
increase
need
What is the purpose of the passage? – to inform the reader of a new problem in climate modeling
In the third paragraph, what does the term “wild card” mean?
an unknown card in a card game
an unknown item in the scientists’ calculations
a large amount of acid dust
none of the above
Direction: Complete a summary of the passage by choosing the sentences that contain the most important information. Three of the answer choices will not be used
Dust particles combine with air containing pollutants from Cairo and southern Israel
Scientists have collected many of the new particles for analysis.
The new particles are important for climate models because they retain moisture and absorb and reflect sunlight
The new particles have chemical properties that are different from those of dry dust particles.
Scientists analyzed the particles at the W.R. Wiley Environmental Molecular Science Laboratory.
Dust particles containing calcite combine with the pollutant nitric acid to form a new particle with new properties.
Complete the conversation by choosing correct word in the blanks.
Why do you look (upset/set up/happy/unhappy)? What are you reading?
I`m reading an article (in/about/for/of) acid dust. It`s really (scare/scared/scary); the dust (reaction/reacts/react/reacted) with pollutants in the air to form wet particles.
You`re too worried (about/for/of/on) the environment.
They reflect sunlight and change clouds. Scientists have never seen (nothing/anything/something) like it.
(reflection/reflect/reflected/reflecting) sunlight and changing clouds doesn`t sound so bad.
Look, if the sunlight is reflected back into space, then plants don`t have enough energy (for/till/to/about) food and oxygen production.
Okay, but what about the clouds (changing/changes/changed/change)?
If the clouds retain water then there won`t be (some/any/no/not) rain.
Uh, no rain (mean/meaning/means/meant) that food can`t grow, right?
Yes, and (bad/worse/worst/not bad).
(who/Which/when/What) do you mean?