[解析]
(1)C.主旨大意题.纵观全文可知文章主要讲述了现在新发明的一种可以让人忘记过去的药片以及人们对这种药片的不同反应.所以C选项正确.
(2)A.细节理解题.根据第三段第二句The drug stops the body releasing chemicals that fix memories in the brain.可知新型药片可以阻止人体产生某种化学物质,所以A选项正确.
(3)D.推理判断题.根据文章倒数第二行All of us can think of bad events in our lives that were terrible at the time but make us who we are.I'm not sure we want to wipe those memories out,可知经历不同的事情能够让我们与别人不同,所以D选项正确.
(4)B.细节理解题.根据第三段They are not sure to what degree people's memories are affected.可知人们对于新药片的持怀疑态度.故B选项正确.