重点讲解:
1. so far 迄今为止;到目前为止;
So far we haven't been able to find anything, but we're still researching.
目前我们还没有任何发现,但是我们仍在研究 。
2. take sth. seriously 认真对待;
We take threats of this kind very seriously.
我们对这类威胁非常重视 。
3. serve as 担任(职务);
She was elected to serve as secretary of the local party.
她当选为地方党组织的书记 。
4. at the expense of 以…为代价;
They are worth having but not at the expense of better services.
它们值得拥有,但是不能因此放弃更好的服务 。