1.sign up 签订合同； 报名

He has posted a sign up that says "No Fishing"
他已经张贴了一张“禁止钓鱼”的告示牌。

They manage to sign up all the best performers.
他们设法跟所有最佳演员签订合同。

3.attempt to 尝试，企图

These feelings are likely to make people attempt to overthrow the system.
这些情绪有可能促使人们想要推翻现行的体制。

The action seemed a clumsy attempt to topple the Janata Dal government.
这一试图推翻人民党政府的行动似乎缺乏策略。