—China is getting better and better at making high technology products.—That's right. People around the world can hardly avoid________ products made in China.
A：not buying
B：not to buy
C：to buy
D：buying
对于函数y=f（x），x∈D，若对任意的x1∈D，存在唯一的x2∈D，使得fx1fx2=M，则称函数f（x）在D上的几何平均数为M，已知f（x）=x3﹣x2+1，x∈1，2，则函数f（x）=x3﹣x2+1在1，2上的几何平均数M=____
等腰三角形的两边长分别是4和9，则这个等腰三角形的周长是（ ）
一 Could you tell me ? I must find him.
一Sorry, I'v no idea. But he was here just now.
