For years scientists have been worried about the effects of air pollution on the earth's natural conditions. Some believe the air inside many houses may be more dangerous than the air outside.
Most scientists agree that every modern house has some kind of indoor pollution. People began to notice the problem in the early 1970s. When builders began making houses and offices, they did not want to waste energy. To do this they built buildings that limited the flow of air between inside and outside. They also used man－made building materials which are now known to let out harmful gases.
As the problem became more serious, scientists began searching for a way to deal with it. They discovered a natural pollution control system for building green plants.
Scientists believe that a plant's leaves absorb the pollutants (污染物). In exchange the plant lets out oxygen through its leaves. Studies of different plants show that each absorbs different chemicals. So the most effective way to clean the air is to use different kinds of plants.
1.Indoor air pollution may be more dangerous than the air outside mainly because .
A. the building are too high
B. the flow of air indoor is limited
C. the building materials are harmful
D. people don't want to waste energy
2.Some kind of indoor pollution can be found in .
A. all kinds of offices B. all kinds of houses
C. every modern house D. every old house
3.In the last paragraph the word“ absorb” may mean .
A. take in B. bring up C. give out D. turn into
4.Scientists believe that plants can .
A. change oxygen into pollutants
B. absorb all the pollutants
C. make your houses more prettier
D. absorb pollutions and let out oxygen
5.According to the last paragraph, we should to clean the air.
A. plant all kinds of plant
B. plant more trees.
C. have the same kind of plant
D. have different kinds of plants
The year is 2094. It has been announced that a comet (彗星) is heading towards the Earth. Most of it will miss our plant, but two pieces will probably hit the southern half of the Earth.
On 17 July, a piece four kilometers wide enters the Earth’s atmosphere(大气层) with a massive explosion. About half of the piece is destroyed, but the remaining part hits the South Atlantic at 200 times the speed of sound. The sea boils and a huge hole is made in the sea bed. Huge waves are created and spread outwards from the hole. The wall of water, a kilometer high, rushes towards southern Africa at 800 kilometers an hour. Cities on the African coast are totally destroyed and millions of people are drowned.
Before the waves reach South America, the second piece of the comet lands in Argentina. Earthquakes and volcanoes are set off in the Andes Mountains. The shock waves move north into California and all around the Pacific Ocean. The cities of Los Angeles, San Francisco and Tokyo are completely destroyed by earthquakes. Millions of people in the southern half of the earth are already dead, but the north won’t escape for long. Because of the explosions, the sun is hidden by clouds of dust, and temperatures around the world fall to almost zero. Crops are ruined. The sun won’t be seen again for many years. Wars break out as countries fight for food. A year later, no more than 10 million remain alive.
Could it really happen? In fact, it has already happened more than once in the history of the Earth. The dinosaurs were on the Earth for over 160 million years. Then 65 million years ago they suddenly disappeared. Many scientists believe that the Earth was hit by a piece of object in space. The dinosaurs couldn’t live through the cold climate that followed and they died out. Will we meet the same end?
1.What is mainly described in the passage?
A. An event of imagination.
B. A scientific adventure.
C. A research on space.
D. A historic discovery.
2.When the first piece hits the South Atlantic , it causes _____
A. an earthquake B. damages to cities
C. an Earth explosion D. huge waves
3.Why can’t the northern half of the earth escape for long?
A. Because the light and heat from the sun can not reach the earth.
B. Because the land is covered with water
C. Because people there can not live at the temperature of zero.
D. Because wars break out among countries.
4.By giving the example of dinosaurs, the author tries to prove______
A. the Earth could be hit by other objects in space
B. what happened 65 million years ago was an invented story
C. the human beings will die out in 2094
D. animals could not live in the cold climate
5.We may guess that the writer is ______________.
A. worried B. practical
C. a scientist D. full of imagination
My First Day
I was still shy before a crowd. And my first day at the new school made me laughed by my classmates. I was sent to the blackboard to write my name. I knew my name, and knew how to write it, but standing at the blackboard with the of so many pupils on my back made my hand __ and I was unable to write a single letter.
“ __ your name,” the teacher called to me. I lifted the white chalk to the blackboard and, as I was about to write, my mind went blank; I could not remember my name, the first letter. Somebody laughed and I became .
“Just forget us and write your name,” the teacher called and walked to my side, at me to give me confidence.
“What’s your name?” she asked.
“Richard,” I whispered.
“Then write it.”
I turned to the blackboard and lifted my hand to write, but then I was again. I tried to collect my senses but I could remember nothing. I how totally I was failing and I grew weak and leaned(斜靠) my hot forehead the cold blackboard. The room burst into a loud and my muscles froze. I sat and myself. Why did I always appear so nervous I was called upon to perform in a crowd? I knew how to write as well as any other pupil in the classroom, and there was no that I could read better than any of them, and I could talk when I was sure of myself. Then why did strange faces make me freeze? I sat with my ears and neck , hearing the pupils around me whisper, hating myself.
1.A. presence B. pressure C. eyes D. smiles
2.A. break B. struggle C. fall D. freeze (冻结)
3.A. Write B. Read C. Spell D. Repeat
4.A. still B. ever C. even D. also
5.A. delighted B. angry C. disappointed D. nervous
6.A. pointing B. smiling C. looking D. waving
7.A. blank B. stupid C. quiet D. empty
8.A. realized B. recognized C. doubted D. guessed
9.A. by B. before C. against D. from
10.A. cheer B. noise C. cry D. laugh
11.A. calmed B. hated C. comforted D. hid
12.A. when B. during C. where D. before
13.A. need B. doubt C. wonder D. use
14.A. freely B. anxiously C. clearly D. correctly
15.A. shaking B. suffering C. hurting D. burning
Tom is not_______as his brother.
A. good as a student B. as good a student
C. as a good student D. a as good student
The police _________ the mountain to ________ the murderer.
A. is searching; search for
B. are searching for; search
C. is searching for; search
D. are searching; search for
He told me that he had mailed part of the samples样本 and that the rest _____ in a few days.
A. were following B. have followed
C. has followed D. was following
