攻丝和套丝的精度较高，可用于精度较高的螺纹。
参考答案：错
简要回答超Y理论的主要内容是什么？
----Where is Tom now, Millie?
----I saw him _______ in the street a moment ago and I told him _________.
A．playing; don’t do so
B．playing; not to do so
C．play; to do so
D．play; don’t do so
