Java的体系结构中，最下层是________，最上一层是_________和___

下列哪种方法对减少或消除流行病学研究中的偏倚无效

A．增加样本量

B．遵循随机化原则

C．实施盲法

D．严格质量控制

E．选择适宜的研究对象

阅读下面短文,根据所读内容在表格中的空白处填入恰当的单词.

注意:每个空格只填一个单词.

       If you are asked to chair a meeting, remember the following six golden rules for meeting management.

      1. Always start the meeting on time. If you begin on time, group members who show up late will realize

the value of time. Beginning on time reflects the skill as an effective time manager and sets an example for

others to follow.

      2. Select a note-taker or arrange to have the meeting audio-taped .You may need to refer back to an

issue that was discussed during the meeting at a later date. Good record-keeping is a sign of a good meeting manager as well.

      3. Learn to listen. So many times we think we are going to say and, in the process, block out important

points that other group members may be contributing. Additionally, we often hear only what we want to hear, rather than really listen to other people. Meetings that are characterized by effective listening are successful

meetings.

      4. Keep the discussion on track .Many times important issues can get sidetracked in a meeting, especially when everyone has a different opinion about the topic. If an unexpected conflict develops once the meeting

is in progress, either appoint a subcommittee to look into the problem, or ask the participants involved in the

conflict to meet with you after the meeting. Doing so will help keep the discussion on track and minimize (减少) the chances of wasting participants' time of great value.

      5. Give everyone an opportunity to be heard .Some people tend to control meetings, whereas others

wait to be asked their opinions. As the leader of the meeting, you need to keep an open mind and make sure

everyone feels welcome to contribute and express ideas without criticism.

      6. End on time. If you said the meeting would last no longer than one hour, make sure the meeting lasts

for only one hour. Running late with a meeting makes members late for other appointments, increases the

chances that the members will mentally leave the meeting and reduces your reliability as an effective meeting

manager.

                                    1.    ▲      on how to manage a meeting

公立医院

销售促进

地下燃气管道不得从建筑物和（）的下面穿越。

A.隧道

B.铁路

C.高速公路

D.大型构筑物