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【简答题】
表示正棱锥的底面的面积,h表示正棱锥的高, 表示正棱锥的斜高,c表示正棱锥底面的周长 =(), =()
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皮皮学刷刷变学霸
举一反三
【简答题】操作系统的体系结构,微内核结构的特点
【多选题】货物或劳务可以采取竞争性谈判方式进行采购的情形有 ( ) 。
A.
招标后没有供应商投标或者没有合格标的或者重新招标未能成立的
B.
技术复杂或者性质特殊，不能确定详细规格或者具体要求的
C.
采用招标所需时间不能满足用户紧急需要的
D.
只有从唯一供应商处采购的
【单选题】Which of the following can NOT be concluded from 'the statement 'it is harder to talk about immigration as an economic issue.'? (Para. 4)
A.
Immigration is often considered as a political or social issue rather than an economic issue in Britain.
B.
Immigrants do not have noticeable impact on British economy.
C.
Immigrants' contribution to the prosperity of Britain is often neglected.
D.
In America, the issue of immigration is mainly about its economic implications.
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