地方性单纯性甲状腺肿最主要的发病原因是（）。 A.妊娠、授乳等因素对甲状腺激素需要量

写出如图所示的游标卡尺和螺旋测微器的读数：

（1）图1所示游标卡尺读数为______mm．

（2）图2所示螺旋测微器读数为______mm．

氮化硼（BN）是一种重要的功能陶瓷材料，以天然硼砂为起始物，经过一系列反应可以得到BN，如下图所示：  

Ⅰ．由H₃BO₃制备B₂O₃的化学方程式是_________；

Ⅱ．某实验小组利用上述反应原理(B₂O₃ + 2NH₃ 2BN + 3H₂O)和如下装置制备氮化硼。

已知：BN高温下能被空气氧化，不溶于水；B₂O₃难溶于冷水但可溶于热水。  

（1）连接好装置后，在各连接处涂抹肥皂水，然后通入N₂检查气密性。证明气密性良好的现象是_____________；通入N₂的另一作用是______________。

（2）瓶B中装有硫酸溶液，作用是_____________。

（3）反应结束时，关闭电炉和活塞K，并立即用弹簧夹夹紧A、B之间的橡皮管，直至___________再转移产物。若没有夹紧橡皮管可能观察到的现象是__________。

（4）欲除去产物中未反应的B₂O₃并得到纯净的BN固体，实验操作过程是__________。

男，45岁，近2个月来感胸闷、心悸、气促、乏力，逐渐出现少尿、下肢水肿。查体：颈静脉充盈，血压90/60mmHg，心浊音界向两侧扩大并随体位而改变，心音低钝，肝大，肝颈静脉回流征阳性。X线提示心脏阴影普遍性向两侧扩大，心脏搏动减弱。

如需与心力衰竭鉴别，最重要的心脏体征是有无()

A.心率增快

B.心音低钝

C.舒张期奔马律

D.心房颤动

E.三尖瓣区或心尖区收缩期吹风样杂音

A project management technique that is currently in widespread use is the (71) . The purpose of this technique is to detail, in hierarchical fashion, all of the activities that are required to meet project objectives. There are some special activities called (72) , which are events that signify the accomplishment or completion of major deliverables during the project. Most system development methodologies also provide (73) , whose purpose is to contain the various pieces of relevant information - feasibility assessments, schedules, needs analysis, and so forth - in a single place so that they can be presented to project clients and other related parties. Several types of important network diagrams are used in project management. (74) was developed to make clear the interdependence between project tasks before those tasks are scheduled． (75) offers the advantage of clearly showing overlapping tasks.

A．Structure Chart

B．Organizational Structure

C．Work Breakdown Structure

D．Functional Decomposition Diagram

参予线路工程竣工验收的人员必须是专业人员。