Plain Ring and Snap Gages for checking the major diameter.

普通环规与卡规是为了检测大径。

youdao

But far from being the height of fashion, Mona Lisa's dress is utterly plain and timeless and, despite the fact that she is a married woman, she wears no jewellery, not even a wedding ring.

这幅画作里的蒙娜丽莎却没有显现出当时的潮流，她穿着的服装朴实无华，完全看不出来她是个已婚的女性，既没有佩戴珠宝也没有戴戒指。

youdao

The merchant took a plain gold ring from his carpet and engraved something on it.

那位商贩从地毯上拿起一枚普通的金戒指，在上面刻了些什么。

youdao