完形填空
Text 1
Avalanche and Its Safety
An avalanche is a sudden and rapid flow of snow, often mixed with air and water, down a mountainside. Avalanches are 1 the biggest dangers in the mountains for both life and property.
All avalanches are caused by an over-burden of material, typically snowpack, that is too massive and unstable for the slope 2 supports it. Determining the critical load, the amount of over-burden which is 3 an avalanche, 4 a complex task involving the evaluation of a number of factors.
Terrain slopes flatter than 25 degrees or steeper than 60 degrees typically have a low 5 of avalanche. Snow does not 6 significantly on steep slopes; also, snow does not 7 easily on fiat slopes. Human-triggered avalanches have the greatest incidence when the snow's angle of rest1 is 8 35 and 45 degrees; the critical angle, the angle at which the human incidence of avalanches is greatest, is 38 degrees. The rule of thumb2 is: A slope that is 9 enough to hold snow but steep enough to ski has the potential to generate an avalanche, regardless of the angle. Additionally3, avalanche risk increases with 10 ; that is, the more a slope is disturbed by skiers, the more likely it is that an avalanche will occur.
Due to the complexity of the subject, winter travelling in the backcountry4 is never 100% safe. Good avalanche safety is a continuous 11 , including route selection and examination to the snowpack, weather 12 , and human factors. Several well-known good habits can also 13 the risk. If local authorities issue avalanche risk reports, they should be considered and all warnings should be paid 14 to. Never follow in the tracks of others without your own evaluations; snow conditions are almost certain to have changed since they were made. Observe the terrain and note obvious avalanche paths where plants are 15 or damaged. Avoid traveling below others who might trigger an avalanche.
e of rest：這裡指積雪保持靜止的角度。
b：指“a broadly accurate principle，based on experience or practice rather that theory”，即“通用法則，經驗法則 ”。
tionally：是一個副詞，用來引人新的事實或論點，意為 “此外”。
country：人煙稀少的地區。
練習:
1. A among B of C to D in
2. A when B that C who D whose
3. A mostly B likely C clearly D surely
4. A are B will be C is D was
5. A weight B form C risk D work
6. A fall B flow C roll D gather
7. A fall B flow C roll D gather
8. A among B between C with D for
9. A thick B thin C flat D rocky
10. A use B time C snow D rain
11. A journey B trip C fact D process
12. A conditions B reports C forecast D event
13. A increase B reduce C improve D remove
14. A price B effort C attention D money
15. A missing B grown C big D fresh
答案與題解：
1.A表達“雪崩是山上可能發生的昀大危險之一 ”的意思，因此應該選擇 among(在……之中)。
2.B從該句的語法結構上來看，此處需要一個關係代詞，代替 slope，所以 that是昀佳選擇。選項 A、C、D均不符合語法。
3.B選項 A不符合語法， C和 D符合語法，但不符合常識：過度的雪的積壓可能導致雪崩，而不是必定導致雪崩。所以， B是昀佳答案。
4.C該句的主語是 Determining the critical load，從上下文來看應該使用一般現在時，所以 C是正確答案。
5.C要確定本題答案的一個有效的方法是排除法。 a low weight/form work of avalanche都不合邏輯，只有 a low risk of avalanche符合上下文的意思。下面的句子解釋了 low risk of avalanche的道理，更證實了選 risk是正確的。
6.D第 6和第 7題可以一起考慮。整個句子的意思是：在坡度大的坡上，雪不會大量堆積。在較為平坦的坡面，雪不會輕易滑動。
7.B(見 6)
8.B理解了句子的意思就不難判斷選項：雪在靜止狀態下，角度在 35～45度之間，昀可能發生人為觸發的雪崩。between：在……之間。
9.C這個句子說明的是什麼樣的山坡昀易發生雪崩，即，A slope that is flat enough to hold snow but steep enough to ski。flat在此做 “平坦”解，與後面的 steep形成反義。
10.A句中的 that is表明，後半部分是對前半部分的進一步說明。所以，這裡的選擇要根據下文的意思判斷。
use是昀佳選擇，整個句子的意思是：山坡被滑雪者使用的越多，雪崩就越可能發生。
11.D儘管選項 A、B和 D都能和 continuous搭配，從全段的內容判斷，只有 process是昀佳選擇，因為該段描寫的是如何防備雪崩，及如何做好安全措施等一系列問題。
12.A選項 A、B、C都可以與 weather搭配，但是根據上下文，只有 A昀為符合文章的內容。
13.B選項 A不符合句子的意思; C不能和 risk搭配;D也不符合句子的意思，因為不可能完全消除雪崩的隱患。
14.C該句主句使用的是被動語態，第二個動詞是 pay attention to的被動形式。選項 A、B、D均不符合句子的意思。
15.A該句是作者給出的一系列忠告之一，即，認真觀察地形，注意明顯的雪崩路徑，沒有植物或植物被毀壞的地方。選項 B、C、D均不符合句義。
Text 2
The First Bicycle
The history of the bicycle goes back more than 200 years. In 1791，Count de Sivrac (1) ________onlookers in a park in Paris as he showed off his two-wheeled invention ，a machine called the celeriferé. It was basically an (2) ________version of a children’s toy which had been in (3) ________ for many years. Sivrac's "celeriferé had a wooden frame，made in the (4) ________ of a horse ，which was mounted on a wheel at either end. To ride it ，you sat on a small seat ，just like a modem bicycle ，and pushed (5) ________ against the (6) ________ with your legs—there were no pedals. It was impossible to steer a celeriferé and it had no brakes，but despite these problems the invention very much (7) ________to the fashionable young men of Paris. Soon they were (8) ________ races up and down the streets.
Minor (9) ________were common as riders attempted a final burst of ( 10 ) ________ . Controlling the machine was difficult ，as the only way to change (11) ________ was to pull up the front of the "celeriferé" and (12) ________it round while the front wheel was (13) ________ in the air. "Celeriferés" were not popular for long ，however ，as the (14) ________of no springs ，no steering and rough roads made riding them very uncomfortable. Even so，the wooden celeriferé was the (15) ________of the modem bicycle.
詞彙：
count / kaunt / n. 伯爵 brake / breik / n. 閘，剎車
onlooker / 'ɔn,lukə / n. 觀眾 burst / bə:st / v. 爆發，突發，爆炸
pedal / 'pedl / n. 踏板，腳蹬子 spring / spriŋ / n. ' 彈簧
steer / stiə / v. 駕駛，操縱，控制 rough / rʌf / adj， 粗糙的，不平整的
譯文：
第一輛自行車
自行車的歷史可以追溯到兩百多年前。1791年，西夫拉克伯爵在巴黎的一個公園裡向眾人展示並炫耀了自己的發明，一架被稱作“celeriferé”的雙輪車。它主要就是一個使用了很多年的兒童玩具的擴大版。西夫拉克的“celeriferé”有一個馬形狀的木框，兩端分別裝有一個輪子。坐上一個小座位便可以騎了，就像騎現在的自行車一樣，但雙腳要使勁蹬地——因為沒有腳踏板。操縱方向和剎車也是不太可能的，儘管有這些問題，這個發明在當時還是吸引了許多巴黎時尚的年輕人。很快他們便舉行了比賽，在街上到處騎。
當騎手嘗試最後衝刺時，受到一些小傷是很普遍的事情。控制那臺機器是很難的，改變行駛方向的唯一方法是拉起車前身，當前輪還在空中打轉時掉轉車頭。然而這種木製雙輪車並沒有流行很長時間，結合了沒有彈簧、沒有方向舵，以及遭遇不平整路段等問題，木製的雙輪車騎起來十分不舒服。儘管如此，這種木製的“celeriferé”還是現在自行車的始祖。
Text 3
Singing Alarms Could Save the Blind
If you cannot see, you may not be able to1 find your way out of a burning building — and that could be fatal. A company in Leeds could change all that2 1 directional sound alarms capable of guiding you to the exit.
Sound Alert, a company 2 the University of Leeds, is installing the alarms in a residential home for 3 people in Sommerset and a resource centre for the blind in Cumbria. 4 produce a wide range of frequencies that enable the brain to determine where the 5 is coming from.
Deborah Withington of Sound Alert says that the alarms use most of the frequencies that can be 6 by humans. “It is a burst of white noise 7 people say sounds like static on the radio,” she says. “Its life-saving potential is great.”
She conducted an experiment in which people were filmed by thermal-imaging cameras trying to find their way out of3 a large 8 room. It 9 them nearly four minutes to find the door _10_ a sound alarm, but only 15 seconds with one.
Withington studies how the brain 11 sounds at the university. She says that the 12 of a wide band of frequencies can be pinpointed more easily than the source of a narrow band. Alarms 13 the same concept have already been installed on emergency vehicles.
The alarms will also include rising or falling frequencies to indicate whether people should go up 14 down stairs. They were 15 with the aid of a large grant from British Nuclear Fuels.
1.在謂語動詞中，不能並列使用兩個情態動詞，如 may和 can就不能並列使用。如果由於表達需要，要同時用“可能”和“能夠”，就得說(寫)成 may be able to。 I may be may be able to come tomorrow, but 1 cannot promise. 我可能明天來，但我不可能作出承諾。 2. that指第一句所表達的意思。
3. … find their way out of…：意為“找到從……出去的路”。練習：
1. A without B with C having D selling
2A run by B changed by C decorated by D criticized by
3. A slow B deaf C blind D lame
4. A Alarms B Alarm C The alarm D The alarms
5. A noise B sound C music D bell
6. A watched B produced C learnt D heard
7. A where B what C that D how
8. A smoked B smoke-filled C filled with smoke D smoke-filling
9. A has taken B takes C took D will take
10. A on B near C without D from
11. A processes B produces C possesses D proceeds
12. A feature B quality C diagram D source
13. A basis on B base on C basing on D based on
14. A on B and C but D otherwise
15. A developed B determined C discovered D delivered
答案與題解：
1. B 空格後是一種裝置，用它來改變火災時找不到出口的危險境況。表達“用……裝置”這層意思就要用介詞 with。其他幾項均不符合句子的意思。
2. A Sound Alert是一家公司的名字， a company是 Sound Alert的同位語，從句意判斷，應選擇 run by，意為“由……經營的”。其他的選項雖然說法正確，但都與句意不符。
3. C 從文章的標題，以及文章內容和本句後面部分 resource center for the blind，可以推斷這裡昀好的選擇就是 C。
4. D 因為這種警告裝置已在上文中提到：第一段中的 directional sound alarms，第二段中的 installing the alarms in a residential home…，所以，這裡的 alarms是特指，要用定冠詞。選項 C是錯誤的，因為它是單數形式。
5. B 句子的前半句有 a wide range of frequencies，發出來的應該是 sound，而不是令人煩躁的 noise。用 music或 bell都有些突然，與上下文的意思不連貫。
6. D 文章一直在討論警報器、聲音和波長，所以首先排除選項 A;從上下文的意思看，不可能是選項 B和 C，因為警報器的製造，就是為了讓失明的人聽到。
7. C 選擇 A、B、D均不能構成語義連貫的句子，而且語法上也有問題。選項 C能使句子結構成為 “It is … that”的強調句型。
8. B 從所給的選項可以看出，這裡要表達的意思是“煙火瀰漫的房間”。有了這個理解，現在要做的.就是選擇正確的表達形式。 A是“煙燻的”， D是“使……煙火瀰漫的”，所以意思不對， C填入後就出現 filled with smoke room，不符合語法。只有 B是正確的選項。
9. C 這裡顯然是“ It takes somebody + time +動詞不定式”的句型，但選擇什麼時態是關鍵。從上句看，應選擇一般過去時，因為整個段落是對一次試驗的描寫，而且上而一句也使用了一般過去時。
10. C後半句的 one指上半句中的 a sound alarm。該句上半句和下半句由 but連線，表示相反的意思，從後半句的 with可以看出，兩個相對比的事物是： the door without a sound alarm和 the door with a sound alarm。所以選擇 C。
11. A 選項 B、C和 D顯然是錯誤的，因為詞義不符。只有選項 A是答案。句子的意思是， Withington在她的大學裡研究大腦如何處理聲音。
12. D 句子中的 more … than表示該句是對兩樣事物的對比。 than後面是 the source of a narrow band，這裡的 narrow和前半句的 wide形成反比，從上下文中可以看出， the source of a narrow band of (frequencies)是和 the source of a wide band of frequencies形成對比。
13. D 這個句子有主語 alarms，有謂語 have been installed，這裡應填入動詞的分詞形式。 be based on是常用的搭配，所以，應選擇動詞的過去分詞形式。選項 A的 basis是名詞，明顯是錯的。
14. A 根據上半句中的 rising or falling frequencies，這裡應填入 or，與上半句表達的意思相一致。音訊升高表示上樓，音訊降低表示下樓。
15. A 首先確定主語 They指的是第一句中的主語 The alarms，後半句說這種裝置得到大筆資助。根據上文內容，我們知道資助的目的是開發這種 alarms，所以應該選擇 developed。
