题目

Jogging is ________ than many sports—to start, just get some comfortable sports clothes and good running shoes. A . cheap B . cheaper C . cheapest D . the cheapest 答案：B在光的色散实验中，光经过三棱镜后，在白屏上形成一条彩色光带，光带的颜色从一端到另一端的颜色依次为________、________、________、________、________、________、________,传播方向改变大的是________．