加工硬化是指加工后金属的塑性降低，强度和硬度增加的现象。
参考答案：对
There are so many kinds of radios in the shop. I can’t decide _________.
A．to buy what
B．to buy which
C．which to buy
D．when to buy
燥湿健脾，祛风散寒的药物是（）
A.草果
B.苍术
C.砂仁
D.白豆蔻
E.干姜
