| Scientists studying the activity of the
living brain with widely used new imaging techniques have been missing some of
the earliest steps in brain activity because those changes are subtle and are
masked by reactions that happen seconds later, Israeli scientists say. The imaging techniques — positron emission tomography scanning and magnetic resonance imaging, known as PET and functional M. R. I. scans — are used prominently in studies of brain activity. The most active brain areas appear to light up on the scans as specific tasks are performed. The two techniques do not measure nerve-cell activity directly; they measure the extra flow of blood that surges to the most active brain areas. Researchers at the Weizmann Institute of Science in Rehovot, Israel, have monitored these changes in blood flow in anesthetized cats by removing parts of the A. The increase in blood masked some of the subtle changes. B. It took three seconds after an event for the flow of blood to increase to an area of the brain. C. The body’s reaction was like watering the entire garden for the sake of one thirsty flower. D. Researchers will use new methods to study human brains because of the limit of conventional imaging techniques. [单选题]常规直流工程的直流功率测控点设置在（____）。
A.A.逆变站直流线路出口 B.逆变站交流线路出口 C.整流站直流线路出口 D.整流站交流线路出口 [单选题]操作人员应按照指挥人员的信号进行作业，当信号不清或错误时，操作人员（）。
A.可自己判断 B.可要求重发 C.可提出疑义 D.可拒绝执行 [判断题]开关设备进行工频耐压试验，如中途间断，可进行“补足剩余时间”的试验。
A.正确 B.错误 [单选题]有砟轨道大型养路机械捣固，两捣一稳作业后，第三日第二列限速为多少
A.160 B.140 C.120 D.100 [判断题]TVM卡纸币时，不需要查看维修屏显示的信息。
A.正确 B.错误 [多项选择]一项完整的出版物发行活动，大体上要经历的阶段有( )。
A. 信息流通与市场沟通阶段 B. 货款结算阶段 C. 出版物商品交易阶段 D. 物流组织阶段 E. 损失报废阶段 我来回答: 提交
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