在△ABC中,AB=AC,点D在AC边上,且BD=BC=AD,则∠A的度数为( )
A:30°
B:36°
C:45°
D:70°
①价值决定价格,价格波动影响供求关系
②价格以价值为基础,供求关系和价格相互影响
③供求关系影响价格波动,价格波动又决定价值
④价值决定价格,价格受供求关系的影响
The technology has been ____(simple) so that anyone can use it.