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【多选题】
下面属于供给价格弹性较小的服务有A.
急救
B.
外科
C.
内科
D.
预防保健
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反馈参考答案：
举一反三
【单选题】About Database, which of the following is WRONG?
A.
Relational model is an obsolete database model now
B.
DBMS means database-management system.
C.
A query is a request to see information from a database that matches specific criteria
D.
A record is a collection of related fields in a database and also called a row
【单选题】系统的根轨迹_____
A.
起始于开环极点，终止于开环零点
B.
起始于闭环极点，终止于闭环零点
C.
起始于闭环零点，终止于闭环极点
D.
起始于开环零点，终止于开环极点
【单选题】Which statement is true about a whole consistent database backup on a database running in ARCHIVELOGmode（）
A.
The backup will consist of used data blocks only.
B.
The database must be shut down to accomplish the backup.
C.
The backup can be accomplished without shutting down the database.
D.
The backup will contain all database files that have never been backed up
【简答题】（1）化简： sin( π 2 +α)?cos( π 2 -α) cos(π-α) + sin(π-α)?sin(-α) sin(π+α) ； （2）设两个非零向量 e 1 和 e 2 不共线，且 AB = e 1 +2 e 2 ， BC =-2 e 1 +3 e 2 ， CD =5 e 1 +3 e 2 ，求证：A，B，D三点在同一直线上．
【简答题】证明 e(φ)×e1(φ)=k； (2)证明 e(φ+α)=e(φ)cos α+e1(φ)sin α．
【单选题】I would rather apologize to my boss for being late without an explanation than ______ an excuse.
A.
fabricate
B.
fake
C.
forge
D.
pretend
【简答题】已知A(r，θ，φ)=r 2 sinφe r +2rcosθe θ +sinθe φ ，求 ． (ρ，φ，z)为柱面坐标，(r，θ，φ)为球面坐标．
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