①AC⊥BD;②∠BAD=90°;③AB=BC;④AC=BD.
A:①③
B:②③
C:③④
D:①②③
综合性学习。
九(1)班开展“走上辩论台”的综合学习活动,请你积极参与并完成下列任务。
Jenny ______ with him at that time, for I was having dinner with her in my home.