with 复合结构，用于句首时，一般应加逗号停顿。

用于句末时，如果句子较短则不需加逗号；如果较长，通常加逗号停顿。网友的前两句含有with 复合结构，加不加逗号均可。

第3句，with 不是复合结构，而是一个介词短语，但由于句子主干较长，也需要加逗号停顿。

She came into the room, with her nose red because of cold. （with 复合结构）

The master was walking up and down with the ruler under his arm. （with 复合结构）

The two ministers signed a memorandum of open understanding in establishing cooperation commissions between the two governments, with the aim of promoting bilateral cooperation. （with 介词短语）

(1)She came into the room, with her nose red because of cold.

她走进房间，鼻子冻得通红。【with+名词+形容词 复合结构】

(2)The master was walking up and down with the ruler under his arm.

老师腋下夹着尺子走来走去。【with+名词+介词短语 复合结构】

(3)The two ministers signed a memorandum of open understanding in establishing cooperation commissions between the two governments, with the aim of promoting bilateral cooperation.

【with+名词+介词短语 复合结构】

两国部长签署了《关于建立两国政府合作委员会的公开谅解备忘录》，旨在促进双边合作。

备注：加逗号主要用于讲话人中间需要停顿。如果内容很短，可以不需要加逗号并一气呵成把话讲完。