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

1.我们可以把换向器拉槽。至于电流表与电压表，我们得送间去调整。

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

2.本文研究在一个有单位中两个倍幂等换位子与两个倍对合换位子可逆性问题。