Since everybody is here，let's begin!

既然大家都来了，咱们就开始吧！

3．as所引出的理由在说话人看来已经很明显，或已为听话人所熟悉而不须用because加以强调。as引导的从句与主句具有同等的地位。

As it is raining，let's do something indoors.

既然下雨了，咱们就做点室内活动吧。

4．now that用来说明一种新情况，然后再加以推论。常译为"既然......，由于......"。

Now that they've got to know each other a little better，they get along just fine.

由于彼此间有了进一步了解，他们相处得不错。

注意：for为并列连词，连接并列句，它表示的原因只是对前一分句补充说明或推断原因，它与前一分句不存在因果关系。它所引导的分句只能放在句子后面。

The day breaks，for the birds are singing.

天亮了，鸟儿都在叫了。(不是直接原因，而是推断的结果。)

Ⅰ.用适当的连词填空

1．If you don't understand something，you may research，study，and talk to other people until you figure it out.(2017·北京)

2．I really enjoy listening to music because it helps me relax and takes my mind away from other cares of the day.(2016·北京)

3．I am not afraid of tomorrow，for I have seen yesterday and I love today.(2016·北京)

4．There is only one more day to go before your favourite music group play live.(2015·四川)

5．We need to get to the root of the problem before we can solve it.(2015·天津)

6．I have heard a lot of good things about you since I came back from abroad.(2013·陕西)

7．Mark needs to learn Chinese since his company is opening a branch in Beijing.(2013·山东)

8．-Coach，can I continue with the training?

-Sorry，you can't as you haven't recovered from the knee injury.(2012·重庆)