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【单选题】
人体组织内引起超声波反射的条件是A.
相邻物质致声衰减能力不同
B.
相邻物质声阻抗存在差别 ( ＞ 0.1 ％ )
C.
声波与界面平行
D.
相邻物质声反射能力相等
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【简答题】各国试图通过国际贸易_________来实现自由贸易的目的和利益。通过国际贸易协议，各国许诺对另一个国家的出口实施_________ 的贸易保护限制，并以另一个国家对其出口作出相同承诺作为回报。某些协议只有两个或少数一些国家参加，诸如北美自由贸易区(NAFTA)；当然也有协议覆盖了世界上的大部分国家。世界贸易组织(wTO)监督全球性贸易协议，它为许多复杂的牵涉国际_______的谈判提供了框架，并...
【简答题】国际市场调研的基本方法有哪些?
【简答题】网络市场调研的基本方法有哪些？
【单选题】It can be learned from the 4th paragraph that
A.
mercury and other preservatives in vaccines do harm to children.
B.
autism has something to do with vaccine.
C.
some people are misled about polio vaccine.
D.
people from politics are positive about polio vaccine.
【简答题】市场调研的基本方法有哪些？
【单选题】It can be learned from the 6th paragraph that______.
A.
old people are surprisingly willing to learn new things
B.
people should be both mentally and physically independent
C.
many non-users of Internet have never used the Internet
D.
social service organizations play important roles in helping the old
【单选题】在国际国际贸易协调中主要是对（）。
A.
关税和非关税贸易政策以及调整国际贸易关系的协调
B.
主要对国家关系的调整
C.
主要对国际关系的调整
D.
主要联合国成员国关系的调整
【单选题】It can be learned from the 7th paragraph that______.
A.
Feinstein knows what the policy-makers are interested in
B.
both genes and family background affect people's educational development
C.
white-collar parents put more effort on their children's education
D.
early performance test can be wrong in some cases
【单选题】Which can NOT be learned from Channel 3 on April 25th, 2009?
A.
Pinyin
B.
English
C.
Japanese
D.
Miao People's language
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