情绪性疲劳的特点是（）。
A.与不愉快的心情相联系
B.休息能够缓解疲劳
C.心情舒畅时，疲劳会减轻
D.看书消遣能够减轻疲劳
参考答案：A, C
So desperate ______ that no one could help another, each ____ to save himself and his animals.
A．was the situation; was trying
B．the situation was; trying
C．the situation was; was trying
D．was the situation; trying
下列说法正确的有（）
A、垂直接地体宜采用长度不小于2.5m的热镀锌钢材
B、垂直接地体间距为垂直接地体长度的1~2倍
C、具体数量可以根据地网大小、地理环境情况来确定，地网四角的连接处应埋设垂直接地体。
D、垂直接地体间距为垂直接地体长度的2~3倍
