【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】一些成年人体内( )活性过低,大量食用乳及乳制品可能引起乳糖不耐受的发生。
【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
【单选题】一些成年人体内( )活性过低,大量食用乳及其制品可能引起乳糖不耐受的发生
【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.
【单选题】已知函数f(x)=-cosx+e x ,则f′(1)的值为( )
【单选题】I would rather apologize to my boss for being late without an explanation than ______ an excuse.
【单选题】一些成年人体内()活性过低,大量食用乳及其制品可能引起乳糖不耐受的发生