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问题 多项选择题

信道利用率是信息在传输过程中的一个重要概念，信道的利用率主要是由以下（）几个因素决定的。

A、数据帧长度

B、信道宽度

C、单程传播延时

D、误码率

E、吞吐率

答案

参考答案：A, B, C

单项选择题 A3/A4型题

女性，58岁，硬腭部出现一个小包块，约1cm，偶有轻微不适。镜下可见肿瘤细胞排列成圆形、卵圆形或不规则的上皮团块，呈筛孔状排列，筛孔中心为黏液样组织，嗜酸性染色。

病理诊断为（）

A.肌上皮瘤

B.黏液表皮样癌

C.腺淋巴瘤

D.多形性腺瘤

E.腺样囊性癌
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单项选择题

Environmental scientist: It is true that over the past ten years, there has been a sixfold increase in government funding for the preservation of wetlands, while the total area of wetlands needing such preservation has increased only twofold (although this area was already large ten years ago). Even when inflation is taken into account, the amount of funding now is at least three times what it was ten years ago. Nevertheless, the current amount of governmental funding for the preservation of wetlands is inadequate and should be augmented.
Which one of the following, if true, most helps to reconcile the environmental scientist’s conclusion with the evidence cited above

A．The governmental agency responsible for administering wetland-preservation funds has been consistently mismanaged and run inefficiently over the past ten years.

B．Over the past ten years, the salaries of scientists employed by the government to work on the preservation of wetlands have increased at a rate higher than the inflation rate.

C．Research over the past ten years has enabled scientists today to identify wetlands in need of preservation well before the areas are at serious risk of destruction.

D．More people today, scientists and nonscientists alike, are working to preserve all natural resources including wetlands.

E．(E) Unlike today, funding for the preservation of wetlands was almost nonexistent ten years ago.
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