共用题干 Avalanche and Its SafetyAn avalanche is a sudden and rapid flow of snow,often mixed with air and water,down a mountainside.Avalanches are _________(51)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 un-stable for the slope. __________(52)supports it.Determining the critical load,the amount of over-burdenwhich is______ (53)to cause an avalanche,_________(54)a complex task involving the evaluationof a number of factors.Terrain slopes flatter than 25 degrees or steeper than 60 degrees typically have a low________(55)of avalanche.Snow does not ________ (56)significantly on steep slopes;also,snow does not__________(57)easily on flat slopes.Human-triggered avalanches have the greatest incidence when the snow'S angle of rest is_________(58)35 and 45 degrees;the critical angle,the angle at which the human incidence of avalanches is greatest,is 38 degrees.The rule of thumb is:A slope that is_________(59) enough to hold snow but steep enough to ski has the potential to generate an avalanche,regardless of the an- gle.Additionally,avalanche risk increases with__________(60);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 backcountry is never 100% safe.Good avalanche safety is a continuous__________(61),including route selection and examination of the snowpack,weather___________(62),and human factors.Several well-known good habits can also __________ (63)the risk.If local authorities issue avalanche risk reports,they should be considered and all warnings should be paid__________(64)to.Never follow in the tracks of others without your own evalua-tions;snow conditions are almost certain to have changed since they were made.Observe the terrain and note obvious avalanche paths where plants are_________(65)or damaged.Avoid traveling below others whomight trigger an avalanche. _________(51)
A.among B.of C.to D.in正确答案A
