正好【zhèng hǎo】
1. just right; just in time; as it happens 2. just enough; flat
[形]1、恰巧遇到机会;碰巧 2、恰好,合适

事故发生时,我正好就在马路对面。
When the accident happened, I was just across the street.

这张卡片正好能装进信封里。
This card just fits nicely into the envelope.
正经【zhèng jing】
1. formal; serious 2. fair
[形]1、正派庄重 2、正当的

那个人作风不正经,不要跟他来往。
Don't associate with that man, for he is crooked.

别浪费时间了,我们还有正经事要做。
Stop footling about. We have serious work to do.
正面【zhèng miàn】
1. facade 2. the right side; front 3. positive
[名]1、主要的一面 2、东西主要使用的一面 [形]3、好的、积极的一面

纪念碑的正面是石料做的。
The facade of the monument is made of stone.

名片正面印的是中文,背面是英文。
My business card is printed in Chinese on the front and in English on the back.

正面的激励,可以调动员工积极性。
Positive stimulus can motivate the staff.