2014年职称英语(理工类)教材完形填空文章及练习(2)

　　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____ cause an avalanche, ____4____ acomplex task involving the evaluation of a number of factors.
　　Terrain slopes flatter than25degrees or steeper than60degrees typically have a low ____5____ of avalanche. Snow does not____6____ significantly on steep slopes; also, snow does not ____7____ easily on flat slopes. Human-triggered avalanches have the greatest incidence when the snow’s angle of rest1 is____8____ 35 and45 degrees; the critical angle, the angle at which the human incidence of avalanches is greatest, is38degrees. 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, die more lijkely 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 of 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.
　　词汇：
　　avalanche / '?v?l?nt?, -lɑ?n? / n.雪崩
　　snowpack / 'sn??p?k / n.积雪场
　　terrain / te're?n / n.地形，地势
　　steep / sti?p / adj.险峻的，陆峭的
　　trigger / 'tr?g?(r) / v.引起，激发
　　incidence / '?ns?d?ns / n.发生(率)
　　ski / ski? / v.滑雪
　　complexity / k?m'pleks?t? / n.复杂性
　　注释：
　　1.angle of rest：这里指积雪保持静止的角度。
　　2.rule of thumb：指“a broadly accurate principle, based on experience or practice rather than theory”，即“通用法则，经验法则'
　　3.Additionally：是一个副词，用来引人新的事实或论点，意为“此外”。
　　4.backcountry：人烟稀少的地区
　　练习：
　　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