In the past two years, the number of campus bookstores offering rentals _____ from a few dozen to

1,500.[ ]

A. jumped

B. had jumped

C. is jumping

D. has jumped

一位病人有行走不稳（夜晚黑暗时加重），行走时双目注视地面，跨步阔大，举足过高，踏步作响，应考虑为：（）

A.小脑性共济失调

B.前庭功能障碍

C.感觉性共济失调

D.下肢痉挛性轻瘫

E.鸭步