A：剪刀的两刀片
B：合页的两页板
C：钓鱼凳的两凳腿
D：伸缩杆的两连杆
P是四边形ABCD内一点，PA=PB=PC=PD，又AB=CD，试确定四边形ABCD的形状，并加以证明．
—It____(mean)we shouldn't____(make)noises here.
—I think buyers________ spend too much time going to shops.
