TDCS系统实时显示信息变化的响应时间应≤4s。
参考答案:对
In their efforts to persuade us to buy that product,shopkeepers have made a close study of human
nature and have __________ all our little weaknesses. [ ]
A. divided
B. arranged
C. classified
D. separated
病例对照研究每个“病例”可配1个“对照”,也可配2个或更多。