关于党的性质“两个先锋队”的阐述脂的是（） A.中国工人阶级的先锋队 B.中国人民的

已知M（a，3）和N（4，b）关于y轴对称，则（a+b）²⁰⁰⁸的值为[ ]

A．1

B．﹣1

C．72007

D．﹣72007

ETF申购、赎回的原则有( )。

A．场内申购、赎回ETF采用份额申购、金额赎回的方式

B．场外申购、赎回采用金额申购、份额赎回的方式

C．场内申购、赎回ETF的申购对价、赎回对价包括组合证券

D．申购、赎回申请提交后不得撤销

运动的物体具有机械能，静止的物体没有机械能。[ ]

Several merchant ships are arriving at the scene of a distress incident. One of the them must assume the duties of the Coordinator Surface Search (CSS). Which of the following statements is TRUE?（）.

A.CSS duties are always assumed by passenger vessels，dry cargo vessels，or tankers in that order of precedence

B.The CSS must be established by mutual agreement between the ships concerned

C.A tanker should never be assigned CSS duties unless only tankers are present

D.The first vessel to arrive at the distress incident is designated as the CSS

城市生态系统具有自然生态系统的某些共性，同时又具有独特的个性 ().

A.人为性和不完整性

B.复杂性和脆弱性

C.聚集性和稀缺性

D.A+B