Videodisc and laser technology provide the ability to（） A: cost more B: enhance other forms of education C: create some education files D: store large amounts of data

According to Professor Healey, we may infer that mentally retarded children perhaps _______. A: need graphic representations in order to understand higher-order language concepts B: are good at studying English idioms but often fail to grasp higher-order language concepts C: are not very patient with videodisc which helps them to understand the world concepts D: tend to be deaf as well and have difficulty learning the simple concept "before and after"