【单选题】在闭式软齿面齿轮传动中,齿轮传动容易出现( )现象。A.齿面胶合
【单选题】In the US, some doctors are now very worried .
A.
about exercise dependence
B.
that people do not exercise enough
C.
that some people do too much exercise
【简答题】数据库管理系统支持的数据模型主要有三种,分别是层次模型、网状模型、______模型。
【简答题】一定能使机体产生反应的刺激为 [填空(1)]A. 阈刺激或阈上刺激
【单选题】Exercise dependence happens when people .
A.
become happy after a lot of exercise
B.
need a lot of chemical-caused happy feelings to feel OK
C.
are addicted to physical and mental happiness
【单选题】在闭式软齿面齿轮传动中,齿轮传动容易出现( )现象。
【简答题】一定能使机体产生反应的刺激为[填空(1)]
【单选题】不同的线有不同的感情性格,线有很强的心理暗示作用,( )给人比较稳定、静态的感觉。