在三棱锥S—ABC中，∠SAB＝∠SAC＝∠ACB＝90°，AC＝2，BC＝4，SB＝4.(1)*：SC⊥B...
问题详情：在三棱锥S—ABC中，∠SAB＝∠SAC＝∠ACB＝90°，AC＝2，BC＝4，SB＝4.(1)*：SC⊥BC；(2)求二面角A—BC—S的大小．【回答】 (1)*由已知∠SAB＝∠SAC＝∠ACB＝90°，以C点为原点，建立如图所示的空间直角坐标系，则A(0,2,0)，B(4,0,0)，C(0,0,0)，S(0,2,2)...
用“sac”造句大全，sac造句
Someofthemodelscontainedanairsac.FluidintheamnioticsacsurroundingthefetusalsocontainsfetalDNA.Perhapswearereallytalkingaboutamnioticfluid,whichsurroundsthefoetusinthebirthsac.Thesmallorgiantaneurysm,a...
用“aneurysmal sac”造句大全，aneurysmal sac造句
Methods:(1)excisionofaneurysmalsacandmicrosuturingforvascularreconstruction;Objective:Tointroducethesurgicaltechniquesofaneurysmalsacexcisionandparentvesselreconstructionintreatmentforgiantaneurysms.T...
用“cul-de-sac”造句大全，cul-de-sac造句
Thecul-de-sacstasisoflifeinthesuburbanmiddleclass?It'slikesayingthebluewhaleisinanevolutionalcul-de-sacbecauseitlivesintheocean.They'realsodifficulttomaintainbecauseyournavigationlogichastostoreinfo...
用“lesser sac”造句大全，lesser sac造句
Thelesserperitonealsacabnormalitiesincludedavarietyofpathologicentities:collection(35cases),liposarcinoma(1cases),andpancreatitis(21cases),pancreaticcarcinoma(13cases),gastriccarcinoma(6cases),gastric...
用“embryo sac”造句大全，embryo sac造句
Thematureembryosachassevencells.Starchgrainspresentintheembryosacandplacentaareutilizedbytheembryo.Thentheuninucleateembryosacforms7-celledor8-nucleateembryosacofpolygonumtypefollowingitsthreetimesdiv...
用“dural sac”造句大全，dural sac造句
1、APduralsacdiameteronaxialandmidsagittalimagesshowedasimilartendency.2、ResultsThenerverootswithinthelumbarduralsacwerearrangedlooselywiththesacralandcoccygealnerverootstoformthecaudaequina.3、Concl...
根据句意及首字母提示填写单词。1.MarycomesfromCanada，soshe'saC
问题详情：根据句意及首字母提示填写单词。1.MarycomesfromCanada，soshe'saC________.ButherChineseisexcellent.2.Therearesomefruit，vegetablesandeggsintheb________.3.ManyplayersgotgoldmedalsintheO________.Theyf...