腌腊是（）原料以花椒盐或硝盐腌制后，再进行烟熏或直接晾干的腌制方法。
A、植物性
B、动物性
C、矿物性
D、菌菇
参考答案：B
什么叫活化剂？它通过哪几种方式来使矿物得到活化？
--- Look at ______ book on the desk . Is it ______ useful one ?
--Yes, it is . In the book there is much advice on how to learn math well.
A．a, the
B．the, a
C．the, an
D．a, an
