对一类相似对象的性质描述的是
A.对象
B.类
C.子类
D.继承
参考答案:B
解析: 类是对一类相似对象的性质描述,这些对象具有相同的性质。
选出句中错误并改正。
( ) 1. My father doesn't works on Friday. ____________________
A B C D
( ) 2. Your brother don't like beautiful dolls. ____________________
( ) 3. She can speaks Chinese. ____________________
( ) 4. Miss Wang often plays piano on Sunday. ____________________
()是指设备、设施或技术工艺含有内在的能够从根本上防止发生事故的功能。
A.本质安全
B.生产安全
C.安全功能
D.安全预防