问题补充：
My command of English is notyours.
A. as half as
B. so half good as
C. good as half as
D. half so good as
答案：
A. as half as
B. so half good as
C. good as half as
(答案→)D. half so good as
解析：考查倍数的表达。倍数在最前边，题中是一半，考查结构为：half as/so…as,句意：我掌握的英语程度不及你的一半好。故选D。
