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[问题2] 我能向对方发消息，对方也能向我发消息，但当对方响应我发出的消息时，我却什么也收不到，这是为什么

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Questions 29 to30 are based on the following news. At the end of the news item, you will be given 10 seconds to answer the questions. Now listen to the news The aid will be increased__________.

A. to the target set by the UN
B. to the target set for 2013
C. to about $12 billion annually
D. by about $12 billion annually

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在自旋回波序列中如何实现T1WI

A. 长TR(1500～2500ms)、短TE(15～25ms)
B. 长TR(1500～2500ms)、长TE(90～120ms)
C. 短TR(300～600ms)、短TE(15～25mS)
D. 短TR(15～25ms)、长TE(1500～2500ms)
E. 短TR(300～600ms)、短TE(25～35ms)

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所谓加权即重点突出某方面的特性。之所以要加权是因为在一般的成像过程中，组织的各方面特性(如：质子密度、T1值、T2值)均对MR信号有贡献，几乎不可能得到仅纯粹反映组织一种特性的MR图像，通过利用成像参数的调整，使图像主要反映组织某方面的特性，而尽量抑制组织其他特性对MR信号的影响，这就是“加权”。T1加权成像是指这种成像方法重点突出组织纵向弛豫差别，而尽量减少组织其他特性如横向弛豫等对图像的影响；T2加权成像重点突出组织的横向弛豫差别；质子密度加权像则主要反映组织的质子含量差别。关于T1wI下列叙述错误的是

A. 主要反映组织T1的差别
B. 采用短TR、短TE
C. 长T1的组织呈低信号
D. 组织信号与T1成正比
E. 脂肪呈高信号

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Usually one and a half hours before departure, the check-in counters open and passengers begin to check in for their flight.A passenger service agent checks the passenger’s ticket and his reservations status. The ticket must be the right one and the status should be OK. If the passenger has any baggage to check in, the agent weighs it and takes care of it. Each first-class passenger has a free baggage allowance of thirty kilograms, and for economy-class passengers the allowance is twenty kilograms. Airlines can charge for overweight baggage.The agent attaches a tag to each piece of checked baggage, and gives the identification tag, i.e. the baggage claim check to the passenger. The passenger claims his baggage with this identification tag upon arrival.Besides, passengers must pay an airport tax. The charge varies from country to country. In the United States it is US $3 for each passenger. In Japan it is Japanese￥2,000, and it’s RMB ￥50 in China.Then the passenger receives a boarding pass. The pass shows the flight number, the class, and the seat assignment. Next he goes to the passport control and the departure gate. How can the passenger claim his baggageWith（）

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