The idea, originated with Bell, of using glass fiber to carry an opticalcommunication signal had to wait some 80 years to be useful because ______.A:people were not interested in this idea B:nobody sponsored this project C:didn’t have suitable glass and low-cost electronics for it D:other reasons 答案: didn’t have suitable glass and low-cost electronics for it作业专业英语基础知识 专业英语基础知识作业