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【简答题】
若a，b，c，d为整数，（a 2 +b 2 ）（c 2 +d 2 ）=1993，则a 2 +b 2 +c 2 +d 2 =______．
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【单选题】听力原文：W: In America, many prisoners are having their cases reviewed, and some have even been freed through DNA testing. M: Then, how about the ones whose death sentence have already been carried out? Q...
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It has helped to find some criminals.
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It has found most criminals.
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It has freed all the innocent people from prison.
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It has freed some innocent people from prison.
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crushing
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cutting
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【单选题】This aesthetic( 美感 ) is just the surface of Apple’s deeper design principle: that ___________-edge technology should be easy to use.
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crushing
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【简答题】科学家们称超导现象是当代科学的“明珠”，假如人们已研制出常温下的超导体，在电炉丝、输电导线、保险丝中，适合用超导材料制作的是______；丹麦物理学家______首先发现电流的磁效应；电磁起重机使用电磁铁而不使用永磁铁的优点是______（写出一条）．
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