任何机关或者单位向农民或者农业生产经营组织收取行政、事业性费用的依据是（）A、法律B

若a⊂α，b⊂β，α∩β=c，a∩b=M，则（　　）

A．M∈c

B．M∉c

C．M⊂c

D．M⊂β

氯化钠在水溶液中的存在形式是（　　）

A．钠离子和氯离子

B．钠原子和氯原子

C．氯化钠分子

D．氯化钠颗粒

患者女，27岁，因“全身疼痛2年余”来诊。近2年出现腰痛、足跟痛、肩背痛等，逐渐加重，伴下肢无力，活动受限，身高降低3cm。病程中有多饮、多尿，间断反酸、胃灼热。无肉眼血尿。查体：P90次/min，BP100/70mmHg；步入病房，皮肤干燥，甲状腺不大；胸廓挤压痛（＋）；心、肺、腹（－）；脊柱四肢无畸形，骨盆压痛（＋）；双下肢无水肿。

下一步处理为（提示：甲状旁腺B超：双侧甲状旁腺区实性占位。99mTc甲氧基异丁基异腈甲状旁腺扫描：相当于甲状腺右叶中下极及左叶下极水平异常放射性增高区，考虑功能亢进的甲状旁腺组织可能性大。）（）。

A.即刻补充维生素D制剂及钙剂

B.联系外科行甲状旁腺手术

C.行颈部CT或MRI检查进一步明确定位

D.监测血钙水平，对症处理

E.骨活检

F.警惕术后出现严重低钙血症，及时补充钙剂及维生素D制剂

下列哪些是由位于下丘脑视上核及室旁核的神经分泌细胞分泌的激素（）

A.血管升压素

B.促甲状腺激素释放激素

C.缩宫素

D.促肾上腺皮质激素释放激素

E.心钠素

In looking at the class structure of an entire system, we may find that its inheritance (1) is either wide and shallow, narrow and deep, or balanced. Class structures that are wide and shallow usually represent forests of (2) classes that can be mixed and matched. Class structures that are narrow and deep represent trees of classes that are related by a common ancestor. There are advantages and disadvantages to each approach. Forests of classes are more loosely (3) , but they may not exploit all the commonality that exists. Trees of classes exploit this commonality, so that individual classes are smaller than in forests. However, to understand a particular class, it is usually necessary to understand the meaning of all the classes it inherits from or uses. The proper shape of a class structure is highly problem-dependent.
We must make similar trade-offs among inheritance, aggregation, and using relation- ships. For example, should the class Car inherit, contain, or use the classes named Engine and Wheel In this case, we suggest that an (4) relationship is more appropriate than inheritance relationship. Meyer states that between the class A and B," (5) is appropriate if every instance of B may also be viewed as an instance of A. The client relationship is appropriate when every instance of B simply possesses one or more attributes of A". From another perspective, if the behavior of an object is more than the sum of its individual parts, then creating an aggregation relationship rather than an inheritance relationship between the appropriate classes is probably superior.

(4)

A．aggregation

B．using

C．composition

D．association