问题补充：
Joan writes than she did 2 years ago.
A. much more careful
B. more careful
C. much carefully
D. more carefully
答案：
A. much more careful
B. more careful
C. much carefully
(答案→)D. more carefully
解析：考查比较级.联系下文than she did 2 years ago可知考查在两个事物中进行比较,结合语境可知此处用副词修饰write,故用副词的比较级,选D.
