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【单选题】
以下哪项不是卢瑟福的原子核式结构理论的主要内容( )
A.
原子的中心有个核,叫原子核
B.
原子的正电荷均匀分布在整个原子中
C.
原子的全部正电荷和几乎全部质量都集中在原子核里
D.
带负电的电子在核外绕核旋转
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【多选题】在滚子推杆盘形凸轮机构设计时,下列作法正确的是 。
A.
凸轮的实际廓线是理论廓线的等距曲线,实际轮廓上各点的向径就等于理论廓线上各点的向径减去滚子半径
B.
滚子半径应小于凸轮理论廓线外凸部分的曲率半径时,可避免推杆运动产生 “ 失真 ” 现象
C.
凸轮的实际廓线与理论廓线具有共同的法线,它们对应的各点处的压力角也相同
D.
凸轮的基圆半径等于其理论廓线的最小向径
【单选题】According the two-year-old boy in the interview, what is the reason for the mother wanting her boy to take part in the basketball camp?
A.
His mother is a basketball fan, too.
B.
His mother knows that he is crazy about basketball.
C.
His mother thinks that this can help him grow taller.
D.
His mother expects his to be an excellent basketball player in the future.
【多选题】在滚子推杆盘形凸轮机构设计时,下列哪些作法是正确的
A.
凸轮的实际廓线与理论廓线具有共同的法线,它们对应的各点处的压力角也相同
B.
滚子半径应小于凸轮理论廓线外凸部分的曲率半径时,可避免推杆运动产生 “失真”现象
C.
凸轮的基圆半径等于其理论廓线的最小向径
D.
凸轮的实际廓线是理论廓线的等距曲线,实际轮廓上各点的向径就等于理论廓线上各点的向径减去滚子半径
【多选题】在滚子推杆盘形凸轮机构设计时,下列哪些作法是正确的( )
A.
凸轮的基圆半径等于其理论廓线的最小向径
B.
滚子半径应小于凸轮理论廓线外凸部分的曲率半径时,可避免推杆运动产生 “失真”现象
C.
凸轮的实际廓线是理论廓线的等距曲线,实际轮廓上各点的向径就等于理论廓线上各点的向径减去滚子半径
D.
凸轮的实际廓线与理论廓线具有共同的法线,它们对应的各点处的压力角也相同
【单选题】The boy, wanting to be independent, _____ his father’s offer to help.
A.
turned away
B.
turned in
C.
turned down
D.
turned out
【单选题】( 16 )若看到程序中有以下事件过程,则可以肯定的是,当程序运行时 Private Sub Click_MouseDown(Button As Integer,_Shift As Integer,X As Single,Y As Single) Print “ VB Program ” End Sub
A.
)用鼠标左键单击名称为 “ Command1 ” 的命令按钮时,执行此过程
B.
)用鼠标左键单击名称为 “ MouseDown ” 的命令按钮时,执行此过程
C.
)用鼠标左键单击名称为 “ MouseDown ” 的控件时,执行此过程
D.
)用鼠标左键或右键单击名称为 “ Click ” 的控件时,执行此过程
【单选题】在滚子推杆盘形凸轮机构设计时,下列哪些作法是错误的( )
A.
凸轮的实际廓线与理论廓线具有共同的法线,它们对应的各点处的压力角也相同
B.
凸轮的基圆半径等于其理论廓线的最小向径
C.
滚子圆半径小于凸轮理论廓线外凸部分的曲率半径时,可避免推杆产生 “运动失真”现象
D.
凸轮廓线为外凸结构的凸轮机构,凸轮的实际廓线与理论廓线是法向等距曲线,实际轮廓上各点的曲率半径就等于理论廓线上各点的曲率半径减去滚子圆半径
【单选题】若看到程序中有以下事件过程,则可以肯定的是,当程序运行时,_____。
A.
用鼠标左键单击名称为“Command1”的命令按钮时,执行此过程
B.
用鼠标左键单击名称为“MouseDown”的命令按钮时,执行此过程
C.
用鼠标右键单击名称为“MouseDown”的控件时,执行此过程
D.
用鼠标左键或右键单击名称为“Click”的控件时,执行此过程
【单选题】The boy, wanting to be independent, turned( )his father’s offer of help.
A.
down
B.
over
C.
up
D.
to
【单选题】According to the twelve-year-old boy in the interview, what is the reason for the mother wanting her boy to take part in the basketball camp?
A.
His mother is a basketball fan, too.
B.
His mother knows that he is crazy about basketball.
C.
His mother thinks that this can help him grow taller.
D.
His mother expects him to be an excellent basketball player in the future.
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