一对直齿圆锥齿轮传动中,两轮轴线夹角必定是90°。
参考答案:错
注水泥塞施工,水泥塞试压压降不超过()为合格。
A、0.3MPa
B、0.5MPa
C、1MPa
D、1.5MPa
Suggestopaedia believes that language learning can occur at a much faster rate than it is often expected if learners can make better use of their ______ powers.