关于IM系统标准的描述中，正确的是
A. 最初由Mirabils公司提出
B. 主要由IEEE负责制定
C. 所有IM系统都使用统一标准
D. RFC2778描述了IM系统的功能
住宅设计中，楼梯踏步宽度不应小于0.26m，踏步高度不应大于 0.175m。扶手高度不应小于0.90m。楼梯水平段栏杆长度大于0.50m时，其扶手高度不应小于()m。楼梯栏杆垂直杆件间净空不应大于0.llm。
A. 0.9
B. 0.95
C. 1.0
D. 1.05
楼梯前室的面积，公共建筑、居住建筑分别不应小于()。
A. 6.00m2，4.50m2
B. 6.00m2，10.00m2
C. 4.50m2，10.00m2
D. 6.00m2，8.00m2
Which of the following is the best example of writing that is likely to be subject to the
A history of an auto manufacturing plant written by an employee during an auto-buying boom.
B. A critique of a statewide school-desegregation plan written by an elementary school teacher in that state.
C. A newspaper article assessing the historical importance of a United States President written shortly after the President has taken office.
D. A scientific paper describing the benefits of a certain surgical technique written by the surgeon who developed the technique.
E. Diary entries narrating the events of a battle written by a soldier who participated in the battle.
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