问题
选择题
Some people believe that they would be better off more adaptive activities in their leisure time, such as establishing relationships and teaching their children．
A．doing
B．to do
C．having done
D．to be doing
答案
答案：A
这里考查的是现在分词做条件状语的用法，句意是：一些人相信他们会更幸福的，如果在空闲时间多做些适应性活动，如建立关系，和教育孩子。选A。