读“日本地图”，回答下列问题。

某高山动物的毛色有深灰色、银灰色和白色，依次受B、b^y和b基因的控制，研究发现：深灰色个体的毛色会随着季节的变化而改变颜色；对深灰色个体身体的某一部位用一定剂量的紫外线处理后，部分个体的该部位长出白色且毛色不再改变．下列分析错误的是（　　）

    Here is a picture. It is a picture of my  1  This is my 2. My quilt is on it. Two baseballs are under it. They are white 3. Look at my desk. A4is on it. I like computer games. A 5is on it, too. It's 9:00. My 6is in my schoolbag and two7are in it. My books are8the floor. My keys are in the desk.9is my ID card? Do you10? Oh, it's in my English book. I like my room. It's nice.

若$2a-3b=0$，则$\frac{a}{b}$的值为（   ）