黄土高原的形成，得到广泛支持的是

A．风成说

B．冰川

C．地震

D．火山灰堆积

The demand for 3M’s optical film is closely related with the World Cup soccer games because the optical film ().

A.is used in LCD and LCD is used in quality televisions and computers

B.is used in LCD and LCD is used to receive audio and video signals

C.is a better receiver of audio and video signals than televisions and computers

D.can be mounted on televisions and computers to improve the quality of images