20g、16MnDR均为压力容器专用钢。
参考答案:错
When I arrived,I saw the place was already______ by two strangers in uniforms. [ ]
A. occupied
B. conquered
C. possessed
D. owned
下列哪个是面向对象程序设计语言不同于其他语言的主要特点
A.继承性
B.消息传递
C.多态性
D.静态连编