来自clear,清楚的，解决了的。

1. The UN pledged to help supervise the clearance of mines.

联合国承诺协助监督扫雷工作。

2. They have to wait for clearance from air traffic control.

他们需要等空中交通管制人员的放行。

3. He has a security clearance that allows him access to classified information.

他获得了安全许可，可以接触机密信息。

4. Thai Airways said the plane had been given clearance to land.

泰国航空公司说，该飞机已经得到降落许可。

5. The lowest fixed bridge has 12.8m clearance.

最低的固定桥下方通行高度为12.8米。