1.financial market 金融市场

There are problems on the financial market that we were not aware of before.
金融市场上存在以前我们没有意识到的一些问题。

Just like the human body, the financial market is interconnected, so when one of its vital organs fail-a big bank-the entire system can collapse.
像人的身体一样，金融市场是相互贯通的，因此当其中一个重要器官失灵—一家大银行—整个系统都面临崩溃。

2.use to 过去常常

It is no use to sermon me.
对我唠叨可没用。

What tool should I use to analyze it?
我应该使用什么工具来分析它？

3.opt to 被选择;可选择

Or, you can opt to lick up her back.
或者你可以选择去舔她的香背。

Mobile users can opt to retrieve only some or all archived documents.
移动用户可以选择检索部分或所有的存档文档。

4.keen to 热衷于

I hear this one from very sophisticated people, keen to show their respect for the scale and scope of China.
我从见多识广的人那儿听到这样的话，他们很热衷于展示自己对中国地大物博的尊敬。