下列不属于按封装邮件种类划分的四大类邮件容器的是（）。A.机要邮件容器 B.普通邮件

某施工企业通过投标获得了某住宅楼的施工任务，地下18层、地下3层，钢筋混凝土剪力墙结构；业主与施工单位、监理单位分别签订了施工合同、委托监理合同。施工单位(总包单位)将土方开挖、外墙涂料与防水工程分别分包给专业性公司，并签订了分包合同。

施工合同中说明：建筑面积23 420m²，工程工期450天，2003年8月1日开工，2004年11月25日竣工，工程造价3 165万元。

合同约定结算方法：合同价款调整范围为业主认定的工程量增减、设计变更和洽商；外墙涂料、防水工程的材料费，调整依据为本地区工程造价管理部门公布的价格调整文件。

业主只需要进行一次招标，与一个施工总承包单位签约，招标及合同管理工作量大大减小，对业主有利，属于施工总承包（）的特点。

A．费用控制

B．进度控制

C．质量控制

D．合同管理

以下有关旅游资源的叙述，正确的是（）。

A.黄河壶口瀑布是重要的人文景观旅游资源

B.黄土高原的塬、梁、峁、沟是典型的地貌景观旅游资源，具有很高的地学科学价值

C.城市游憩景观吸引旅客的最根本的原因是其具有经济价值

D.云冈石窟属于自然景观

Proper arrangement of classroom space is important to encouraging interaction. Most of us have noticed how important physical setting is to efficiency and comfort in our work. College classroom space should be designed to encourage the activity of critical thinking. We may be approaching the twenty-first century, but step into almost any college classroom and you step back in time at least a hundred years. Desks are normally in straight rows, so students can clearly see the teacher but not all their classmates. The assumption behind such an arrangement is obvious. Everything of importance comes from the teacher.
With a little imagination and effort, unless desks are fixed to the floor, the teacher can correct this situation and create space that encourages interchange among students. In small or standard-size classes, chairs, desks, and tables can be arranged in a variety of ways. The primary goal should be for everyone to be able to see everyone else. Larger classes, particularly those held in lecture halls, unfortunately, allow much less flexibility.
Arrangement of the classroom should also make it easy to divide students into small groups for discussion or problem-solving exercises. Small classes with movable desks and tables present no problem. Even in large lecture halls, it is possible for students to turn around and form groups of four to six. Breaking a class into small groups provides more opportunities for students to interact with each other, think out loud, and see how other students’ thinking processes operate all essential elements in developing new modes of critical thinking. In courses that regularly use a small group format, students might be asked to stay in the same small groups throughout the course. A colleague of mine, John, allows students to move around during the first two weeks, until they find a group they are comfortable with. John then asks them to stay in the same seat, with the same group, from that time on. This not only creates a comfortable setting for interaction but helps him learn students’ names and faces.

The primary purpose of desk rearrangement is ______.

A. for the teacher to divide students into small groups
B. to make it possible for students to interact with each other
C. for the teacher to find out how students think
D. to give students more opportunities to practice speaking

启泵时，平衡盘未打开，与（）相研磨，致使平衡盘严童磨损，造成窜量过大

A.平衡套

B.叶轮

C.轴套

D.密封圈

动态数据配置通用操作步骤中，在打开“操作”菜单下的[命令行参数表]，依次加入所需命令字时，一次加入的命令字不要超过（）条。