1. What I have learned from the past jobs is the ability to promote products.

我从以往的工作中学到了推销产品的能力。

还能这样说：

I have obtained the ability to promote the products from the past jobs.

I have learned how to promote the products from the past jobs.

应用解析：

a man of ability 有本事的人;

ability in music 音乐天才

2. It has inspired me to develop my ability of personnel management.

这激发了我进行人事管理的能力。

还能这样说：

It has excited my ability to personnel management.

It has aroused the ability to manage the personnel affairs.

谚语：

A cat has nine lives.

吉人天相。

3. I'm very familiar with this market.

我对这个市场非常熟悉。

还能这样说：

I have a good knowledge of this market.

I know about this market very well.

应用解析：

bill market 汇兑市场;

black market 黑市

4. I have realized teamwork is the key to success.

我明白了只有发挥团队的力量才是成功的关键。

还能这样说：

I get to know that teamwork can make us succeed.

I know that only we are united to work can we be successful.

谚语：

Cheek bring success.

和气生财。