Read the following passage and mark the letter (A, B, C or D) on your answer sheet to indicate the correct answer to each for the question from 43 to 50.
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 , ” said Alexander Laskin, a senior research scientist at the Department of Energy’s Pacific Northwest National Laboratory in Richland, Washington .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 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 2,00 individual particles and observed the physical and chemical changes at the W.R Wiley Environmental Sciences Laboratory.
A key change in the properties of the newly formed nitrate particles is that they begin to absorb water and retain the 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 . Companion studies of dust samples from the Sahara and the Saudi coast and loess from China show that the higher the calcium in the mineral , the more reactive they are in with nitric acid .And once the particle is changed , it stays that way.
“When dust storms kick up these particles and they enter polluted areas , the particles change ,” Laskin said . “To what extent this is happening globally, as more of the world becomes industrialized , we don’t know . But now we have the laboratory and field evidence that shows it is definitely happening . The story is much more complicated than anybody thought .”
Why does the passage begin with a description of the properties of calcium nitrate?
A. To give background information so the reader can understand the topic better
B. Because calcium nitrate is the main idea
C. They show how elements combine to create calcium nitrate
D. To prove the existence of calcium nitrate
Giải bởi qa.haylamdo.com
Đáp án là A
Tại sao tác giả bắt đầu bài đọc bằng sự mô tả các đặc điểm hóa học của canxi nitrat?
A. Để cung cấp sự hình thành nền tảng vì vậy người đọc có thể hiểu chủ đề tốt hơn.
B. Bởi vì canxi nitrat là nội dung chính.
C. Để thể hiện các phân tử kết hợp như thế nào để tạo ra canxi nitrat.
D. Để chứng minh sự tồn tại của canxi nitrat
Read the text below and decide which answer (A, B, C or D) best fits each space.
LIVING A HEALTHIER LIFE
Keeping fit and healthy may seem difficult, but there are a few easy-to-follow guidelines. Firstly, a balanced diet is absolutely essential. This (31)_______selecting food that is low in salt and sugar. Experts recommend reducing the amount of fat in your diet, as too much can lead to heart problems. They also suggest increasing the (32)_______of high fiber food we eat. This comes in the form of fresh fruit, vegetables, whole meal bread and pasta. As well as being packed with vitamins and minerals, they are delicious too. Secondly, it’s important to fit exercise into your daily (33)_______This can be done by simply walking as much as possible and climbing stairs instead of taking the lift. Exercise is necessary to maintain a healthy body, as well as increasing energy levels and (34)_______you feel generally fitter and happier. Finally, staying relaxed is important for good health. Too much stress can lead to a variety of illnesses, from headaches to high blood pressure. (35)_______possible, do things you enjoy and treat yourself occasionally. So the message is simple- enjoy yourself but learn to respect your body too. It’s all a question of getting the balance right
Điền vào ô số 31
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to the sentence given in each of the following questions
She forgot about the money until she got home.
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to the sentence given in each of the following questions
As I didn’t want to disappoint my parents, I agreed to go to medical school
Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions
It is difficult to assess grass _______ opinion on the subject of the President ‘s actions
Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the rest in the position of the main stress in each of the following questions
Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions
It’s time you _______ up your mind about what you are going to do with your life
Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions
_______ few species that live on the ground, most monkeys live in trees
Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions
I think everyone should be _______ with the way office machinery works
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to the sentence given in each of the following questions
Seeing that the bad weather had set in, we decided to find somewhere to spend the night
Read the text below and decide which answer (A, B, C or D) best fits each space.
LIVING A HEALTHIER LIFE
Keeping fit and healthy may seem difficult, but there are a few easy-to-follow guidelines. Firstly, a balanced diet is absolutely essential. This (31)_______selecting food that is low in salt and sugar. Experts recommend reducing the amount of fat in your diet, as too much can lead to heart problems. They also suggest increasing the (32)_______of high fiber food we eat. This comes in the form of fresh fruit, vegetables, whole meal bread and pasta. As well as being packed with vitamins and minerals, they are delicious too. Secondly, it’s important to fit exercise into your daily (33)_______This can be done by simply walking as much as possible and climbing stairs instead of taking the lift. Exercise is necessary to maintain a healthy body, as well as increasing energy levels and (34)_______you feel generally fitter and happier. Finally, staying relaxed is important for good health. Too much stress can lead to a variety of illnesses, from headaches to high blood pressure. (35)_______possible, do things you enjoy and treat yourself occasionally. So the message is simple- enjoy yourself but learn to respect your body too. It’s all a question of getting the balance right
Điền vào ô số 34
Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions
These girls are heading for a _______ They get to work late and spend hours talking on the phone
Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions
The effects of the anesthetic _______ after a couple of hours
Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that best joins each of the following pairs of sentences in each of the questions
We stayed out all night. We wanted to watch a meteor storm
Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions
We can’t possibly make any _______ for her, however sweetly she asks
Mark the letter A, B, C or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges
Henry : “ do you think they will lose ? ” Kathy : “Oh ! _______.”
