关键

例句：

1. 1. The key to success is hard work and determination.
   成功的关键是努力和决心。
2. 2. The meeting was a crucial decision point.
   这次会议是一个关键的决策点。
3. 3. The new policy is pivotal in solving the problem.
   新政策在解决问题上至关重要。