完形填空
lightergases
Dalton wondered why the heavier and lighter gases in the atmosphere did not separate as oil and water do. He finally concluded that the constituent __1__ must exist in the form of tiny particles or atoms and that these must be completely mixed together in the __2__. This threw a new light in the laws of definite proportions. It was __3_ necessary to suppose that the atoms could combines into small groups of uniform __5__ and so form more complex substance; thus the mystery of this law was __5__ . Dalton suggested, for example, that carbon monoxide __6__ formed by the one with one pairing of atoms of carbon and oxygen, __7_ carbon dioxide results from a single atom of carbon uniting with two atoms __8__ oxygen. Assuming this to be true, then the definite proportions of Prout′s law would naturally __9_ the relative weights of the many __10__ kinds of atoms.
1. A. gases B. pieces C. things D. gas
2. A. sky B. atmosphere C. oxygen D. environment
3. A. only B. too C. that D. extremely
4. A. construct B. structure C. piece D. feature
5. A. solved B. discovered C. broke D. told
6. A. must B. been C. were D. is
7. A. while B. when C. therefore D. also
8. A. from B. in C. of D. for
9. A. describe B. unit C. mix D. reveal
erent B. usual C. important D. chemical
參考答案:1.A2.B3.A4.B5.A6.D7.A8.C9.B10.A
sunshine
Health experts have given sunshine a bad reputation, for good reason. After all, too much sun put you at increased risk of skin cancer. But several studies found that careful and brief sun ___1___ may fight disease.
Catching few rays may help ___2___ colon cancer by stimulating your skin to manufacture vitamin D. most adults don′t get enough so-called sunshine vitamin, probably because we avoid dietary source of D ___3___ fortified milk and dairy products. Measured doses of sunlight can help ___4___ the shortfall. A large-scale eight-year study revealed that people with the highest levels of vitamin D in their blood were ___5___ to get colon cancer. The main reason is ___6___ vitamin D seems to prevent cancerous changed in cells and also causes the bowel to ___7___ calcium, an anticancer mineral. Exposing your arms and chest___8___the sun for just 10 minutes a day in summer, and 20 minutes a day in spring and fall, can ___9___ vitamin D levels to the colon cancer-fighting range. For most people, this amount of sun is ___10___ increase the risk of skin cancer. But after this brief period of sun exposure, use sunscreen to protect your skin.
1. [A]explosion[B] exposure[C] expansion[D]exhibition
2. [A]ease[B] decrease[C] reduce[D]coMBAt
3. [A]because of [B] such as[C] in spite of[D]for example
4. [A]make out[B] make for[C] make up for[D]make over
5. [A]most[B] more[C] least[D]less
6. [A]that[B] why[C] what[D]whether
7. [A]absorb[B] receive[C] accept[D]abuse
8. [A]under[B] in[C] to[D]for
9. [A]lift[B] rise[C] arise[D]raise
10. [A]very small to[B]small enough to [C] too small to[D]so small to
參考答案：1.B 2.D 3.B 4.C 5.C, 6.A 7.A 8.C 9.D 10.C
atmosphere
Space is a dangerous place, not only because of meteors (流星) but also because of rays from the sun and other stars. The atmosphere again acts __1__ our protective blanket on earth. Light gets through, and this is essential __2__ plants to make the food which we eat. Heat, __3__ , makes our environments tolerable and some ultraviolet rays (紫外線的.) penetrate the atmosphere. Cosmic (宇宙的) rays of various kinds come __4__ the air from outer space, but a great quantity of radiation from the sun are screened off. __5__ men leave the atmosphere they are exposed to this radiation; but their spacesuits or the walls of their spacecraft, if they are inside, __6__ prevent a lot of radiation damage. Radiation is the greatest known danger to explorers in __7__ . Doses of radiation are measured in units called “rems (雷目)”. We all __8__ radiation here on earth from the sun, from cosmic rays and from radioactive minerals. The “__9__” dose of radiation that we receive each year is about two milligrams; it __10__ according to where you live, and this is a very rough estimate.
1. A. for B. with C. on D. as
2. A. with B. from C. under D. for
3. A. again B. also C. besides D. too
4. A. across B C. from D. through
5. A. As soon as B. As well asC. As much as D. As possible as
6. A. get B. make C. have D. do
7. A. earth B. atmosphere C. space D. environment
8. A. receive B. accept C. bring D. catch
9. A. conventional B. commonC. general D. normal
10. A. shifts B. converts C. modifies D. varies
參考答案:1.D 2.D3D4.D5.A6.D7.C8.A9.D10.D
Main Street
Shopping habits in the United States have changed greatly in the last quarter of the 20th century. ___1___ in the 1900s most American towns and cities had a Main Street. Main Street was always in the heart of a town. This street was ___2___ on both sides with many various businesses. Here, shoppers walked into stores to look at all sorts of merchandise: clothing, furniture, hardware, groceries. ___3___ , some shops offered services. These shops included drugstores, restaurants, shoe repair stores, and barber or hairdressing shops. ___4___ in the 1950s, a change began to take place. Too many automobiles had crowded into Main Street while too few parking places were available to shoppers. Because the streets were crowded, merchants began to look with interest at the open spaces ___5___ the city limits. Open space is what their car-driving customers needed. And open space is what they got ___6___ the first shopping center was built. Shopping centers, or rather malls, started as a collection of small new stores ___7___ crowded city centers. Attracted by hundreds of free parking space, customers were drawn away from ___8___ areas to outlying malls. And the growing popularity of shopping centers led, in turn, to the building of bigger and better stocked stores. By the late 1970s, many shopping malls had almost developed into small cities themselves. In addition to providing the ___9___ of one stop shopping, malls were transformed into landscaped parks, ___10___ benches, fountains, and outdoor entertainment.
1. A. As early as B. EarlyC. Early as D. Earlier
2. A. built B. designed C. intended D. lined
3. A. Apart from B. However C. In addition D. As well
4. A. suddenly B. Abruptly C. Contrarily D. But
5. A. over B. from C. out of D. outside
6. A. when B. while C. since D. then
7. A. out of B. away from C. next to D. near
8. A. inner B. central C. shopping D. downtown
9. A. cheapness B. readiness C. convenience D. handiness
10. A. because ofB. and C. with D. provided
參考答案:1.B2.D3.C4.D5.D6.A7.B8.D9.C10.C