We can machine the commutator and voltameter,we have to deliver them to the shop for rectifying.

我可以把换向车光并拉槽。至于电流表与电压表，我得送到车间去调整。

This paper is a study on the invertibility of the commutator of scalar-idempotent elements and scalar-involutory elements of a unitary ring.

本文研究在一有单位元的环中幂等元的换位子与对合元的换位子的可逆性问题。