35.(2023•武清区校级模拟)在四边形ABCDABCDABCD中,AB→=2DC→\overrightarrow{AB}=2\overrightarrow{DC}AB=2DC,AB=4AB=4AB=4,BC=AD=2BC=AD=2BC=AD=2,则AC→⋅BD→=\overrightarrow{AC}\cdot \overrightarrow{BD}=AC⋅BD=___−6-6−6___;若EEE,FFF分别是边BCBCBC,ABABAB上的点,且满足BEBC=AFAB=λ\frac{BE}{BC}=\frac{AF}{AB}=\lambdaBCBE=ABAF=λ,则当AE→⋅DF→<0\overrightarrow{AE}\cdot \overrightarrow{DF}<0AE⋅DF<0时,λ\lambdaλ的取值范围是 [ ].