问题
选择题
________ on ten years of observation and study, Professor Wang announced that everyone dreams every night，whether they realize it or not.
A．Basing
B．Based
C．Been based
D．Having based
答案
答案：B
B [考查过去分词形式作状语。句意：基于10年的观察和研究，王教授声称，每个人每晚都会做梦，不管他们是否意识到了。]