继电保护装置中,过电流继电器接在电流互感器的一次侧。
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继电保护通常由测量比较、逻辑判断、执行输出三部分组成。
A. 对
B. 错
对中性点不接地系统,当发生单相接地时,不必立即跳闸,可根据系统发生单相接地故障时电流大小及方向特征,实现故障检测与选线。
A. 对
B. 错
Listen to a short passage three times . When the passage is read for the first time , listen for its general idea. When the passage is read for the second time, fill in the blanks with the exact words you hear. When the passage is read for the third time, check what you have written.New wordsstatus /'staetas/ n.社会地位evaluation /I vaelju'eifn/ n.评价;评估lottery /lbtori/ n.抽彩给奖法[音频]According to a new study, happiness in life has more to do with respect and influence than wealth . Researchers say that they got interested in this idea because there is abundant 1)that higher income or wealth does not contribute to happiness much at all. At the same time, many theories suggest that higher status should 2) happiness .The researchers put their idea to the test in a set of studies. First, they 3)80 college students. The amount of respect the students received from their peers was 4)based on peer evaluation, self-reports and the number of leadership positions the students held. The researchers also 5)the students’ family income and asked them about their social well-being. They found the admiration from their peers 6)their social well-being. However, their wealth or income did not. Similar results 7)in another study with a larger group of students.In a final study, the researchers followed graduate students in business schools. They found the MBA students' social well-being 8) changes in the respect they felt from their peers before and after graduation. They noted that respect had more to do with the students' well-being after graduation than the money they made.One of the reasons why money doesn't buy happiness is that people quickly 9) the new level of income or wealth.Lottery winners, for example, are initially happy but then return to their 10) level of happiness quickly, What can last is the feeling of being respected, having influence and being socially connected.
某磁盘的转速为7200r/min,传输速度为4MB/s,控制器开 销为1ms。要保证读或写一个512B的扇区的平均时间为11.3ms,那么该磁盘的平均寻道时间不超过()。
A. 3.9
B. 4.7
C. 5.5
D. 6.1