如图，已知AB∥EF，CD⊥BC，∠B=x°，∠D=y°，∠E=z°，则

A.x+y-z=90              B.x-y+z=0           C.x+y+z=180         D.y+z- x =90

如图，已知AB∥EF，CD⊥BC，∠B=x°，∠D=y°，∠E=z°，则

A.x+y-z=90              B.x-y+z=0           C.x+y+z=180         D.y+z- x =90

如图，已知AB∥EF，CD⊥BC，∠B=x°，∠D=y°，∠E=z°，则

1. A.
   x+y-z=90
2. B.
   x-y+z=0
3. C.
   x+y+z=180
4. D.
   y+z- x =90