Questions 5 to 7 will be based on News Item 3.[音频]5
A. Some new laws.
B. A new set of medical guidelines.
C. Some sophisticated rules.
D. Some campaigns.
6
A muscle tear.
B. A serious knee injury.
C. A brain injury caused by medical errors.
D. A brain injury caused by a sudden blow.
7
A. Young athletes who may have a concussion should be taken off the field as gently as possible.
B. Young athletes who may have a concussion should be kept where they are until health care professionals arrive.
C. Only health professionals are qualified for evaluating and caring for concussions.
D. A doctor's written approval is necessary for an athlete with a concussion to return to the sport.
n阶方阵A可对角化的充要条件是A有n个相异的特征值.
A. 对
B. 错
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