在这个地区，要时刻保持警惕和戒备。

Zài zhège dìqū, yào shíkè bǎochí jǐngtì hé jièbèi.

In this area, one must always be vigilant and on guard.

国家领导人在国际会议前要加强戒备。

Guójiā lǐngdǎo rén zài guójì huìyì qián yào jiāqiáng jièbèi.

National leaders should strengthen security measures before international conferences.

在野外露营时，要保持高度戒备。

Zài yěwài lùyíng shí, yào bǎochí gāodù jièbèi.

When camping in the wilderness, maintain a high level of alertness.