问题
选择题
(2013·北京西城区高三期末)Being more realistic，the elderly have learned to focus on things that make them happy and let go of ________ that don't.
A．them
B．it
C．that
D．those
答案
答案：D
句意：更现实的是，年龄大的人已经学会了集中精力于让他们感到高兴的事，并放弃那些不能让他们高兴的事。此处those＝things。