优质碳素钢依含碳量的不同,分为低碳钢.中碳和高碳钢,其中中碳钢含碳量为()。
A.0.7-1.3%
B.0.6-0.8%
C.0.25-0.6%
D.2.5-4%
参考答案:C
In the United States, the black people are often referred to as ______ in which the colour of their skin that caused them troubles and sufferings is NOT mentioned in English euphemisms. ( )
A.niggers
B.negroes
C.the black
D.African Americans
()使用同步(如在线交流)和异步(线程化讨论)手段使建设项目参与各方结合一定的工作流程进行协作和沟通。
A.建设项目协同工作层
B.个性化设置层
C.工作流支持层
D.数据安全层