Helen is 15 years old, and Joan is 15, too. So Helen is ____ Joan.
A. as big as B. as older as C. as old as D. so old as
Helen is 15 years old, and Joan is 15, too. So Helen is ____ Joan.
A. as big as B. as older as C. as old as D. so old as
C 考查as+形容词原级+as意为“与……一样……”。此处指年龄一样大，用old而
不用big。肯定句中用as ... as而不能用so ... as。故选C。