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【单选题】
关于索引描述错误的是以下的哪一个（）
A.
表中的任何数据列都可以添加索引
B.
创建索引的列最好不要含有许多重复的值
C.
一般不给很少使用的列添加索引
D.
并不是数据库中聚集索引越多搜索效率就越高
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举一反三
【单选题】We ____ see air but we ____ breathe it.
A.
can't, can
B.
shouldn't, must
C.
daren't, can
D.
mustn't, must
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【简答题】Three things are necessary for us to keep alive. What are they? They are air, water and food. We eat food twice 46 three times a day. We drink water several times a day. We breathe air day and 47 . If...
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【单选题】There _____ many kinds of birds around here, but now we seldom see them because of the air pollution. [     ]
A.
had
B.
used to have
C.
used to be
D.
are
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【单选题】TCP对应于OSI参考模型的传输层,下列说法正确的是( )。
A.
在IP的基础上，提供端到端的、面向连接的可靠传输
B.
提供一种可靠地数据流服务
C.
当传输差错干扰数据或基础网络出现故障时，由TCP来保证通信的可靠
D.
以上均正确
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【单选题】We can't see air, ________, it does exist.
A.
still
B.
but
C.
and
D.
however
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【单选题】根据药物剂型分类方法,下列关于葡萄糖输液描述不正确的是( )
A.
按给药途径分 : 属人体营养补液
B.
按形态分 : 属液体剂型
C.
按分散系统分 : 属溶液型
D.
按制法分：属灭菌制剂
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【单选题】There _____ many kinds of birds around here, but now we seldom see them because of the air pollution. [     ]
A.
use to
B.
use to have
C.
use to be
D.
are
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【单选题】—Look, there _____ many birds around here, but now we seldom see them. What a pity! —Yeah! The air pollution has caused the problem! [     ]
A.
are
B.
used to have
C.
used to be
D.
use to have
查看完整题目与答案
【单选题】There _____ many kinds of birds around here, but now we seldom see them because of the air pollution. [     ]
A.
use to
B.
use to have
C.
used to be
D.
are
查看完整题目与答案
【单选题】—Look, there_____ many birds around here, but now we hardly see them. What a pity! —Yeah! The air pollution has caused the problem!
A.
are
B.
used to have
C.
used to be
D.
use to be
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相关题目：
【单选题】We ____ see air but we ____ breathe it.
A.
can't, can
B.
shouldn't, must
C.
daren't, can
D.
mustn't, must
查看完整题目与答案
【简答题】Three things are necessary for us to keep alive. What are they? They are air, water and food. We eat food twice 46 three times a day. We drink water several times a day. We breathe air day and 47 . If...
查看完整题目与答案
【单选题】There _____ many kinds of birds around here, but now we seldom see them because of the air pollution. [     ]
A.
had
B.
used to have
C.
used to be
D.
are
查看完整题目与答案
【单选题】TCP对应于OSI参考模型的传输层,下列说法正确的是( )。
A.
在IP的基础上，提供端到端的、面向连接的可靠传输
B.
提供一种可靠地数据流服务
C.
当传输差错干扰数据或基础网络出现故障时，由TCP来保证通信的可靠
D.
以上均正确
查看完整题目与答案
【单选题】We can't see air, ________, it does exist.
A.
still
B.
but
C.
and
D.
however
查看完整题目与答案
【单选题】根据药物剂型分类方法,下列关于葡萄糖输液描述不正确的是( )
A.
按给药途径分 : 属人体营养补液
B.
按形态分 : 属液体剂型
C.
按分散系统分 : 属溶液型
D.
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查看完整题目与答案
【单选题】There _____ many kinds of birds around here, but now we seldom see them because of the air pollution. [     ]
A.
use to
B.
use to have
C.
use to be
D.
are
查看完整题目与答案
【单选题】—Look, there _____ many birds around here, but now we seldom see them. What a pity! —Yeah! The air pollution has caused the problem! [     ]
A.
are
B.
used to have
C.
used to be
D.
use to have
查看完整题目与答案
【单选题】There _____ many kinds of birds around here, but now we seldom see them because of the air pollution. [     ]
A.
use to
B.
use to have
C.
used to be
D.
are
查看完整题目与答案
【单选题】—Look, there_____ many birds around here, but now we hardly see them. What a pity! —Yeah! The air pollution has caused the problem!
A.
are
B.
used to have
C.
used to be
D.
use to be
查看完整题目与答案