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问题 计算题

有条河流，流量Q=2 m3/s，落差h=5m，现利用其发电，若发电机总效率为50%，输出电压为240V，输电线总电阻为R=30Ω，允许损失功率为输出功率的6%，为满足用户220V的照明需求，则该输电线路的使用的理想升压、降压变压器的匝数比各是多少？能使多少盏“220V，100W”的电灯正常发光？（g取10m/s2）

答案

6∶125；235∶11；470盏

听力题

单词拼写 10分

小题1:The army organized teams to dig out those who were trapped and to b_________ the dead.

小题2:In spite of such a big difference in a________ towards what one eats, there is no doubt that people in the west regard the Chinese food as something special.

小题3:The buildings were completely d________ by the earthquake.

小题4:From his d_____________ look we knew nothing could change his mind.

小题5:One may never know the p__________ of knowledge without being educated.

小题6:I didn't r________ her at first because I hadn't seen her for five years.

小题7:The manager thought he was a r__________ person and told him all the plan.

小题8:My son has s________ happily in America.

小题9:She insisted that she o_________ the trip properly.

小题10:Even though she is a foreigner, she can speak Chinese f__________.
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填空题

植物细胞的生物氧化途径除（）和（）途径外，还有（）、（）、（）、（）几种非线粒体氧化体系。
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