securely

The door was securely fastened.

门牢牢地关上了。

The offices were securely guarded.

办公室的保卫措施很到位。

This certificate is an important document, and should be kept securely (= in a place where it cannot be lost or stolen).

这张证书是很重要的文件，应该妥善保管。

Please ensure that your seat belts are fastened securely.

请确保你们的安全带系紧了。

He has given up political power, but he remains securely in control of the army.

他放弃了政治权力，但仍然牢牢掌握着军队的控制权。