1.a cause for concern 令人担心的;引起关注
The state of the country's jails was a cause for concern.
这个国家监狱的状况令人担心 。
2.drawback 缺点
He felt the apartment's only drawback was that it was too small.
他感觉这个公寓惟一的缺点就是太小 。
3.unfulfilled 未实现的
Do you have any unfulfilled ambitions?
你有什么未实现的抱负吗?
4.simmer 即将爆发
This argument has been simmering for months.
这场争论已酝酿了几个月了 。