通读下面的短文,掌握其大意,然后从各小题所给的四个选项中, 　　ProbablyyouhaveseenphotosoftheGrandCanyon.Butyoumustgothere16tofeelitssizeandbeauty.TheGrandCanyonisoneofthegreatest 　　17wondersoftheworld. 　　TheColoradoRivermadetheGrandCanyonovermillionsofyears.Slowly,therivercutdown18hardrocks.Atthesametime,thelandwas19.Todaythecanyonisvery20.It’salsovery21,about20kilo- 　　metres.And22itsheight,therearedifferentkindsofplantsandanimalsonbothsidesofthecanyon. 　　Thecanyonlooksdifferentatdifferenttimesoftheday,and23differentseasonsandweather.Atsunrise,thered,gold,brownandorangecoloursoftherocksare24clearandbright.WhetheryouseetheGrandCanyonfromthetoporthebottom,itwillbea(n)25thatyouwillneverforget. 　　()16.A.youB.yourC.yoursD.yourself 　　()17.A.naturalB.modernC.ancientD.national 　　()18.A.alongB.throughC.acrossD.past 　　()19.A.riseB.risingC.roseD.risen 　　()20.A.moreB.dangerousC.deepD.low 　　()21.A.longB.deepC.highD.wide 　　()22.A.asaresultB.becauseof 　　C.thankstoD.thanksfor 　　()23.A.inB.onC.atD.for 　　()24.A.especiallyB.friendlyC.hardlyD.differently 　　()25.A.interviewB.tripC.visitD.experience 　　16-20DABBC21-25DBAAD