The 2012 London Olympic Games _________ to attract several billion TV viewers around the globe.

A．is expected

B．will be expected

C．are expected

D．has been expected

按照记忆的干扰理论，晚上睡觉前记忆的效果好是因为少了（）。

A.前摄抑制

B.倒摄抑制

C.自然消退

D.前摄抑制和倒摄抑制