A: Dale, welcome to my room!

B: Wow， ____room is nice and tidy．

A: Thanks．

B: Is this a(n) ____?

A: Yes, it is. This model plane is white. Look! Here is a yellow one．

B: ____ is that in your bookcase?

A: It's a tape player. But it's not  ____.

B: Is it your brother's?

A: Yes.

B: ____the radio? Is it your brother's, too?

A: No, it's my radio．

下列关于$\sqrt{12}$的说法中，错误的是（ ）。