Heightisjustoneofthethousandsoffeaturesyourgenes（基因）decide．Infact，becauseyouhavetwoparents，yourgenesprovideyouaheightthatusuallylandssomewherebetweentheheightofeachparent．Ifbothyourparentsaretall，thenmostprobablyyouwillbetall，too．Butifyouhavequestionsabouthowtallyou'regoingtobe，askyourdoctorifheorshecanhelpyoufinditout．

Butgenesdon'tdecideeverything．Forexample，eatinganunhealthydietcankeepyoufromgrowingtotheexpectedheight．Butgettingenoughsleepandexercisewillmeetyourneed．

Itscertainthatyou'rewonderinghowfastyoushouldgrow．Itdepends．There'snoperfectorrightanswer．Generallyspeaking，kidsgrowabout2inches（6cm）ayearbetweenage3andthetimewhentheystartadolescence．

Don'tbescaredifyouseemtohavegrownalotinaveryshorttime．Everyonehasatimetogrowfastestduringadolescence．Theageforstartingadolescenceisaboutloforgirlsandabout11forboys．Butitcanbeearlierorlater--between7and13forgirlsand9and15forboys．

You'llusuallybegintonoticethatyou'regrowingfasteraboutayearorsoafteryourbodystartstoshowthefirstchangesofadolescence．

1．Whatdoestheunderlinedword“adolescence”meaninChinese?

A．婴幼儿时期 B．童年时期 C．青春期 D．学生时期

2．Ifyouwanttoknowhowfastandhowtallyoushouldgrow，________．

A．youshouldeatahealthydiet B．youshouldhaveenoughsleep

C．youcanseekmedicalhelpfromadoctor D．youshouldhaveenoughexercise

3．Thispassageismainlyabout________．

A．howthegenesworkinyourbody B．howyougrowtoacertainheight

C．whenisthetimeyougrowfast D．whyyoulooklikeyourparents

4．Afterreadingthispassage，wecanexplain________．

A．whathealthydietis B．howgooditistobeadoctor

C．howmuchsleeptimeweneed D．whygenescan'tdecideeverything

5．WhichofthefollowingsentencesisNOTrightaccordingtothepassage?

A．You．maybeanxioussometimeswhenyougrowtoofast．

B．Boys'ageforstartingadolescencei