细小的奥氏体晶粒能使奥氏体等温转变图右移，降低了钢的临界冷却速度，所以绌晶粒的钢具有较高的淬透性。
参考答案：错
决定市场结构的因素包括()
A.市场集中度
B.市场行为
C.市场绩效
D.产品差异化
E.进入和退出壁垒
(66) is defined as the buying and selling of products and services over the Internet. It had included the handling of purchase (67) and funds transfers over computer networks from its inception.
A．Electronicmail
B．Searchengine
C．Multimedia
D．Electroniccommerce
