计算题:有一双头右螺旋螺纹,导程S为5mm,求螺距P?
参考答案:
He is a man of few words and it is hard to ________ his thoughts.
A.see
B.tell
C.read
D.say
证券交易市场又称“二级市场”或“次级市场”,是已发行和新发行的证券通过买卖交易实现流通转让的市场。 ( )