She keeps a very tight lid on her own private life.

她对自己的私生活守口如瓶。

It has kept a tight lid on spending for the vaunted Reconstruction and Development Programme (RDP) that is meant to improve the life of the masses.

非国大严格控制了大肆宣传的旨在改善广大群众生活的“重建与发展规划（RDP）”的开支。