阅读理解。

Youcanfindoutmanythingsaboutatreebystudyingitsrings.

Eachyearfromtoptobottomatreegrowsanewlayer(层)ofwoodarounditself.Ifyoucutacrossa

treetrunkorbranchesyouwouldseethattheselayersofwoodlooklikerings.Bycountingtreeringsyou

cantellhowoldthetreeis.Ifyoucounttenringsforexamplethetreeistenyearsold.

Lookingatthepictureshownaboveyoucanseethateachtreeringhasadarkpartandalightpart.The

lightpartwoodgrowsinthespringthedarkpartwoodinwinter.Lookalsothatsomeringsinthepicture

arewideandothersarenarrow(窄).Treesgrowaideringsduringtheyearswhentheygetalotofwaterand

sun-light.Byexaminingtreeringsyoucantellwhattheweathermaywaslikemanyyearsago.

Giantsequoia(红杉)treessuchastheoneinthephotoabovegrowinnorth-westernCalifornia.Someof

thesesequoiashavemorethan3000treerings.Canyouguesshowoldsuchatreewouldbe?

1.Accordingtothestoryatreeringisa______.

[ ]

A:branch

B:layerofwood

C:giantsequoia

D:tenyearsold

2.Atreeringisaddedtoatree______.

[ ]

A:everytenyears

B:everyyear

C:every3000years

D:everytwoyears

3.Thelightpartofatreering______.

[ ]

A:getsdarkinthewinter

B:tellsthetree'sage

C:growsinthespring

D:getslighteveryyear

4.Fromthestoryyoucantellthat______.

[ ]

A:alltreeringslookthesame

B:mosttreesdonotgrowtreerings

C:treeringsaddtothetree'swidth

D:mostofthetreesgrowrings

5.Lookatthedrawingabove.Ifthiswereaslice(片)fromatreetrunkhowoldwouldthetreebe?

[ ]

A:Fiveyearsold.

B:fivemonthsold.

C:Sixyearsold.

D:Tenyearsold.