字典翻译 问答 小学 英语 【Lighttravelsataspeedwhichisaboutamilliontimesfasterthanthespeedofsound.Youcangetsomeideaofthisdifferencebywatchingthestartofarace.Ifyoustandsomedistanceawayfromthestarteryoucanseesmokefromhis】
问题标题:
【Lighttravelsataspeedwhichisaboutamilliontimesfasterthanthespeedofsound.Youcangetsomeideaofthisdifferencebywatchingthestartofarace.Ifyoustandsomedistanceawayfromthestarteryoucanseesmokefromhis】
问题描述:

Lighttravelsataspeedwhichisaboutamilliontimesfasterthanthespeedof sound.Youcangetsomeideaofthisdifferencebywatchingthestartofarace.If youstandsomedistanceawayfromthestarteryoucanseesmokefromhisgun beforethesoundreachesyourears.

Thisgreatspeedoflightproducessomestrangefacts.Sunlighttakesabout8minutestoreachus.Ifyoulookatthelightofthemoontonightrememberthatthelight raysleftthemoon1.3secondsbeforetheyreachedyou.Theneareststarissofar awaythatthelightthatyoucanseefromittonightstartedtotraveltowardsyou fouryearsagoataspeedofnearly2millionkm.perminute.Insomecasesthe lightfromoneoftonight’sstarshadstartedonitsjourneytoyoubeforeyouwereborn.

Thusifwewanttobehonestwecan’tsay“Thestarsareshiningtonight.”We havetosayinstead“Thestarslookpretty.Theywereshiningfouryearsagobut theirlighthasonlyjustreachedtheearth.”

1.Lightspeedis______soundspeed

A.asfastas

B.amilliontimesslowerthan

C.aboutmillionsoftimesfasterthan

D.aboutamilliontimesfasterthan

2.Ifyoustand200metersawayfromamanwhoisfiringaguntostartaraceyouwillfindoutthat______.

A.youcanhearthesoundbeforeyouseethesmoke

B.thesounddoesnottravelasfastaslight

C.thesoundwillreachyoubeforethemanfires

D.soundtravelsaboutamilliontimesfasterthanlight

3.Sunlightobviously(明显地)______thanthelightofthemoon

A.hastotravelagreaterdistance

B.moveslessquickly

C.travelsmuchmorequickly

D.islesspowerful(有力的)

4.Thescientificwayofsaying"Thestarsareshiningtonight"shouldbe______.

A.thestarshavebeenshiningallthetime

B.thestarsseentonightwillshinefouryearslater

C.

董悦丽回答:
  1.D2.B3.A4.C1.D事实细节题。由第1段第1句可知。2.B推理判断题。由第1段最后一句推出。3.A推理判断题。由第2段的第2句(太阳光到达地球需要8分钟)和第3句(月光到达地球仅需1.3秒)...
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