LiBingwasbornduringtheWarringStatesPeriod.HewasanofficialfromtheStateofQin.Around277B.C.，LiBingreceivedanorderwhichcontrolledthefloodinChengdu.

Withthatspecialtaskinmind，LiBingdidverywidefieldstudyinandaroundChengdu.Around256B.C.，heandhissondecidedtoputtheirideatothetest.TheybuiltDujiangyanabout56kilometers(or35miles)westofChengdu.Theirdesignhadthreeimportantparts.

ThefirstpartiscalledYuzui.Yuzuimeans"fishmouth"inChinese.Itwasaman-madeisland.Itcontrolshowmuchwatereachstreamgets.ThesecondpartiscalledFeishayan.Itisreallyaspillway(泄洪道)thatforcesthesandandlittlestonesfromtheinnerrivertotheouterriver.ThethirdpartiscalledBaopingkou.Itcontrolshowmuchwaterfromtheinner(内部的)riveristobeusedforirrigation(灌慨).

LiBingandhissonspentnearlyfiveyearsonbuildingDujiangyan.Theyfinisheditaround251B.C.

Bytoday'sstandardDujiangyanmaybenotsoprefect.Buttotrulyappreciate(欣赏)Dujiangyanwemustrememberthatitwasbuiltmorethan2200yearsago.BackthentheChinesedidnothaveanymodernmachines.Buttheystillmademanygreatthingstheyhadonhand.JustlikethattheybuiltDujiangyan.Itisamazingisn'tit?

根据短文内容，选择最佳答案。

( )1.When did Li Bing begin tobuiltDujiangyan?

A. Around277B.C.

B. Around256B.C.

C. Around251B.C.

D. Around246B.C.

( )2.HowlongisDujiangyan?

A. 56kilometers.

B. 35miles.

C. 2，200meters.

D. Thispassagedidn'ttellus.

( )3.What's the man-made islandinDujiangyanusedfor?

A. Forcingthesandandlittlestonesfromtheinnerrivertotheouterriver.

B. Controllinghowmuchwaterfromtheinnerriver.

C. Controllinghowmuchwatereachstreamgets.

D. Controllinghowmuchwaterisusedforirrigation.

( )4.WhichofthefollowingisNOTtrueaccordingtothelastparagraph?

A. Dujiangyanwasn't prefect atthattime.

B. Dujiangyanwasbuiltover2，200yearsago.

C. AncientChinesemademanygreatthingsbyhand.

D. Thewriter thin