The number of people flying first class on domestic flights rose sharply in 1990, doubling the increase of the previous year. A. doubling the increase of B. doubling that of the increase in C. double as much as the increase of D. twice as many as the increase in E. twice as many as the increase of B除了that有问题外,后面的in也不可以用。请问,这里的in和of究竟有何本质区别?能否举例告知?