The________woman_______Shanghai since her husband______ in 1990．

A．alone；has gone to：died

B．alone；has left：died

C．1onely；has been in；died

D．1onely：has been to：has died

四面体ABCD中，AD与BC互相垂直，且AB＋BD＝AC＋CD．则下列结论中错误的是( )

A．若分别作△BAD和△CAD的边AD上的高，则这两条高所在直线异面

B．若分别作△BAD和△CAD的边AD上的高，则这两条高长度相等

C．AB＝AC且DB＝DC

D．∠DAB＝∠DAC