A、Forty percent. B、Seventy percent. C、Forty five percent. D、Seventy five percent. D细节题。本题选项都是百分数，提示我们在听到百分数时要做一下笔记，并要分清其对应的内容是什么

Good afternoon, every one! I wonder if you know that Americans have always had great faith in education. They believe that all citizens must have s6me education in order to understand economic and political matters and to vote wisely. They also believe that education is essential to social progress. The public schools of the United States are not controlled by the national government nor by church authorities but by the local communities themselves, with state laws setting educational standards and ruling on compulsory attendance. By 1970, seventy-five per- cent were graduating from high school and forty five percent were beginning college or other advanced study. With so much of the population attending school, education is made various in form, to meet the students’ various needs. Students are also allowed a choice of subjects. Methods of teaching vary widely, too. American schools are equipped with a large variety of learning aids.