问题
选择题
A firm from New Zealand has revealed a set of robotic legs which they claim will soon allow ________ wheelchair-bound people to walk again.
A．extremely
B．previously
C．actually
D．eventually
答案
答案：B
副词辨析。A.非常；极端的B. 预先；以前C.实际上D. 最后；终于。根据题意，一个来自新西兰的公司揭示了一组他们声称不久会让以前受困于轮椅的人们重新走起路来的机械腿。故选B。