A:Convinced; about
B:Convincing; about
C:Convinced; of
D:Convincing; of
我国某地质勘探队在某地钻取地下岩芯,钻取的岩芯样本如图所示,图中各类岩石均为沉积岩。读图,回答下列问题。
12-9=____8+9=____14-9=____18-9=____
6+9=____11-9=____9+9=____2+9=____