[单选题]电流互感器二次回路所接仪表或继电器线圈,其阻抗必须()。( )
A.高
B.低
C.高或者低
D.即有高也有低落

Signs of deafness had given him great anxiety as early as 1798. For a long time he successfully concealed it from all but his most intimate friends, while he consulted physicians and quacks with eagerness. But neither quackery nor the best skill of his time availed him, and it has been pointed out that the root of the evil lay deeper than could have been supposed during his lifetime. Although his constitution was magnificently strong and his health was preserved by his passion for outdoor life, a post-mortem examination revealed a very complicated state of disorder, evidently dating from childhood (if not inherited) and aggravated by lack of care and good food. The touching document addressed to his brothers in 1802, and known as his "will" should be read in its entirety. No verbal quotation short of the whole will do justice to the overpowering outburst which runs in almost one long unpunctuated sentence through the whole tragedy of Beethoven’s life, as he knew i
A. an artist does not understand conventional morality
B. Philistines expect geniuses to be morally conventional
C. Beethoven lived within a conventional moral code
D. Don Giovanni abuses conventional standards

Scientists at Johns Hopkins have discovered "striking" differences between men and women in a part of the brain linked with ability to estimate time, judge speed, visualize things three-dimensionally and solve mathematical problems.
47)The differences, the researchers say, may underlie well-known trends that vary by sex, such as the fact that more men than women are architects, mathematicians and race-car drivers.
In a study reported this week in the Journal Cerebral Cortex, the researchers show that a brain region called the inferior parietal lobule is significantly larger overall in men than in women. The area is part of the cerebral cortex and appears on both sides of the brain just above ear-level.
Also, there’s a symmetry difference, with men having a larger left IPL than right. 48) In women in the study, it’s the right IPL that’s somewhat larger, though the difference between the two sides of the brain is