专题推荐： 2011年12月英语四级考试备考冲刺专题

　　Today, most countries in the world have canals.Many countrieshave built canals near the coast, and parallel 1_ the coast.Evenin the twentieth century, goods can be moved more cheaply byboat than by any other 2 _of transport.These 3_ make itpossible for boats to travel 4_ ports along the coast withoutbeing 5_ to the dangers of the open.Some canals, such as theSuez and the Panama, save ships weeks of time by making their6_ a thousand miles shorter.Other canals permit boats to reachcities that are not 7 _on the coast, still other canals 8_ landsswheresthere is too much water, helpto 9_ fields wherethere is not enough water, and 10_ water power for factories and mills.The size ofa canal 11 _on the kind of boats going through it.The canal must be wide enough to permit two ofthe largest boats using it to 12_ each other easily.It must be deep enough to leave about two feetof water 13_ the keel of the largest boat using the canal.When the planet Mars was first 14_through a telescope, people saw that the round disk of the planet was criss-crossed by a 15 _ofstrange blue-green lines.These were called“canals” 16 _they looked the same as canals on earth17_ are viewed from an airplane.However, scientists are now 18 _that the Martian phenomena arereally not canals.The photographs 19_ from space-ships have helped us to 20_ the truth aboutthe Martia“canals”.
　　1.A.off B.with C.to D.by
　　2.A.way B.means C.method D.approach
　　3.A.waterways B.waterfronts C.channels D.paths
　　4.A.among B.between C.in D.to
　　5.A.revealed B.exposed C.opened D.shown
　　6.A.trip B.journey C.voyage D.route
　　7.A.lain B.stationed C.set D.located
　　8.A.escape B.drain C.dry D.leak
　　9.A.water B.wet C.soak D.irrigate
　　10.A.furnish B.afford C.offer D.give
　　11.A.focuses B.bases C.depends D.takes
　　12.A.cross B.pass C.move D.advance
　　13.A.down B.below C.beneath D.off
　　14.A.studied B.researched C.surveyed D.observed
　　15.A.few B.number C.deal D.supply
　　16.A.although B.because C.so D.if
　　17.A.that B.where C.when D.as
　　18.A.exact B.definite C.certain D.decisive
　　19.A.held B.taken C.got D.developed
　　20.A.find B.expose C.uncover D.discover