英语专业八级改错模拟题
Vitamins,likeminerals,arechemicals.Thereisabsolutelynotdifferenceinthechemicalstructure ofthenaturevitaminCandthechemicalstructure ofthesyntheticvitaminC.Also,whilemostsub- stancesareharmlessatverylowlevelofintake,all substance--eventheelementsthatareessentialtolife--canbedangerousifyouoverdothem.Takewaterforexample.Sixoreightglassesadaywillkeepyourbodyingoodfluidbalance.Butyoucanalsobedrown init.Somepeoplearguethatindividualsvarygreatly intheirneedfornutrients,itcannotnecessarilybestatedanygivenamountistoomuch;thatisall relative.Butsincethereislittlesolidinformationonwhatistheoptimalintakeofanyessentialnutrientinhealthyindividuals,itwouldbeimpossibletogiveguidelinesthattaketheseproportionalneedsintothe account.Justaswithotherdrugs,therelationto differentvitamindosagesvaries,withsomepeoplebetterablethanotherstotoleratelargeamounts.Whilewedoknowthatveryspecificallywhatthetoxiclevel 相关资料 |