根据翻译，用now that/because/since/as/for 完成句子。

1. ____ you have finished your work, you'd  better have a rest.

    既然工作已经做完了,你最好休息一下.

2. — Why did you do this?

          你为什么这么做?

    — _____ it is good for you.

          因为这对你有好处.

3. _____ you have known it ,I won't repeat it .

    既然你已经知道了,我就不重复了.

4. Wear strong shoes____we shall do a lot of walking.

    穿上结实的鞋子,因为我们要走不少路.

5. It rained last night , _____   the ground is wet.

   昨晚下雨 了,因为地面是湿的.

简述保泰松与别嘌醇联合应用治疗痛风的优缺点。