1. now that …… 既然…… [让步从句]
eg. Now that the decision has been made, we must try our best to carry it out.
2. unless…not… [ 让步从句]
eg. It is a vicious cycle and unless you consider these social, economic and environmental problems in one context, you are not serious about meeting the challenges. [注意例句中的consider sth. in one context句型:把什么事情放在一起加以综合考虑]