【单选题】Why can't the man go traveling?
B.
He doesn't like to fly.
【简答题】图所示为二级斜齿圆柱齿轮减速器。已知:齿轮1的螺旋线方向和轴Ⅲ的转向,齿轮2的参数m n =3mm,z 2 =57,β 2 =14°;齿轮3的参数m n =5mm,z 3 =21。试求: (1)为使轴Ⅱ所受的轴向力最小,齿轮3应选取的螺旋线方向,并在图b上标出齿轮2和齿轮3的螺旋线方向; (2)在图b上标出齿轮2、3所受各分力的方向; (3)如果使轴Ⅱ的轴承不受轴向力,则齿轮3的螺旋角β 3 应取...
【简答题】He/delay/a/won't/hopes/there/be
【单选题】下列何药为妇科调经止痛之要药,并被李时珍誉为“气病之总司,女科之主帅”
【简答题】He hopes to fly to the moon. ( )