问题补充：
She isn’t her sister Tina.
A. more smarter than
B. so smarter as
C. more smart than
D. as smart as
答案：
A. more smarter than
B. so smarter as
C. more smart than
(答案→)D. as smart as
解析：形容词smart的比较级是smarter，故排除C；A选项中more不能放在比较级前面，而so…as中间应该用形容词的原级，故应排除B。所以本题选D。
