单项选择题 加强应用基础研究,拓展实施国家重大科技项目,突出关键共性技术、前沿引领技术、现代工程技术、颠覆性技术创新,为建设科技强国、质量强国、航天强国、网络强国、交通强国、数字中国、智慧社会提供有力支撑。（ ） A.对B.错

单项选择题 A BJT has measured dc current values of IB = 0.1 mA and IC = 8.0 mA. When IB is varied by 100 μA, IC changes by 10 mA. What is the value of the βdc for this device? __

单项选择题 Many children are addicted to computers, so they often _____ their parents and play computer games for hours every day. A. clash B. hinder C. deny D. defy