—My son is lost . Have you seen a boy passing by here?

—I saw        boy hidden behind          tree over there . You may go and have a look.

A．a; the

B．the; the

C．a; a

D．the; a

《关于“十一五”深化电力体制改革的实施意见》强调，要形成与市场经济相适应的电价机制，实行有利于节能环保的电价政策。这主要表明 ( )

A．供求关系影响价值，造成价格波动

B．电价的形成不受价值规律的影响

C．价格影响供求

D．我国的市场经济体制存在缺陷