—Could you please offer me a job in your company?
—Sorry,I'm afraid it's beyond my________.
人体的各种生命活动主要受到____的调节,也受到____调节的影响.
世界上最大的热带雨林区是
已知:如图,在四边形ABCD中,AB∥CD,E,F为对角线AC上两点,且AE=CF,DF∥BE.
求证:四边形ABCD为平行四边形.