下面第2题是基于以下的说明:设有供应商关系S和零件关系P如图所示。它们的主码分别是“供应商号”和“零件号”。而且,零件关系P的属性“供应商号”是它的外码,属性“颜色”只能取值为(红,白,蓝)(这里假定DBMS不支持级联修改功能)
今向关系P插入新行,新行的值分别列出如下
Ⅰ.('201','白','S10')
Ⅱ.('301','红','T11')
Ⅲ.('301','绿','B01')
它们中()不能被插入。
A. 只有Ⅰ
B. 只有Ⅰ和Ⅱ
C. 只有Ⅱ
D. Ⅰ、Ⅱ和Ⅲ
查看答案
Why did FBI deem it impossible to produce a useful profile of a possible shooter?
A. Because the occasional behavior. on a checklist of warning signs cannot be proof of an adolescent's violent inclination.
Because not all the shooters show violent behavior. in their daily life.
C. Because the Columbine massacre in 1999 did not give us anything new or valuable.
D. Because the school shooters do not have anything in common.
The word "flip" (Pare. 2) most probably means______.
A. decline
B. intensify
C. fluctuate
D. reverse
第二节
听下面5段对话或独白。每段对话或独白后有几道小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。听每段对话或独白前,你将有5秒钟的时间阅读各个小题;听完后,各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
听力原文:W: Waiter, can you come here for a second please?
M: What' s the problem, ma' am?
W: This soup is cold.
M: I'm sorry. I'll bring you some hot soup.
Why does the woman ask the waiter to come?
A. Because she wants to eat food
Because the soup is cold
C. Because she' 11 pay the bill
【B7】
A. Taking
B. Taken
C. Having taken
D. Being taken