2010年上海世博会中国馆——“东方之冠”（如图）的主体结构是用国产Q460钢制成的．下列有关Q460钢的性质中，属于化学性质的是

The elephant is ____. 

    Bai Ling was happy yesterday. Because it was her father's birthday. She boughtgifts for him. And they took pictures in the park. In the afternoon, they ate delicious food. Bai Ling has a pen pal. He is Pat. He lives in the US. Yesterday he came here. He sang and danced. Oh, he also bought gifts. We had a good time.

已知$f\left(x\right)$是定义域为R的奇函数， $f\left(-4\right)=-1$,$f\left(x\right)$的导函数$f^{\text{'}}\left(x\right)$的图象如图所示， 若两正数a,b满足$f\left(a+2b\right)<1$，则$\frac{a+2}{b+2}$的取值范围是(     )