图中所示电阻箱两接线柱间的电阻值为____ Ω。
读“太阳黑子与温带乔木年轮相关性曲线图”,回答小题:
必须世世代代继承和弘扬伟大的民族精神,民族精神的核心是( )
Brown made his mind work hard to learn computer technology.