【单选题】冬虫夏草来源于()。
E.
麦角菌科真菌冬虫夏草寄生在蝙蝠蛾科昆虫幼虫上的子座及幼虫尸体的复合体
【判断题】茯苓来源于多孔菌科真菌茯苓的干燥菌核。 A. 对 B. 错
【简答题】凸轮机构的压力角是指从动件 与力方向的夹角。
【单选题】凸轮机构的压力角是指不计摩擦时,凸轮与从动件接触处的 与从动件上受力点的速度方向之间所夹的锐角。
【简答题】阅读理解。 Bruno was a boy of eight. His father worked in a cinema and his mother worked in a shop. He lived not far from his school. He always walked there and walked home. On his way to school, he had to...
【简答题】凸轮机构的压力角是指:从动件受到的凸轮正压力的方向与力作用点的______方向所夹的锐角。
【单选题】钢筋绑扎时,箍筋间距的允许偏差为( )。
【单选题】绑扎独立柱时,箍筋间距允许偏差为±20mm,其检验方法是( )。
【单选题】直动滚子从动件盘形凸轮机构的压力角是指( )所夹的锐角。