But be on guard for symptoms.

但要注意症状 。

We need to stay on guard.

我们要保持警惕。

African Union soldiers are on guard near the line.

非盟的士兵在队伍附近守卫。

Everard, Arthur's on guard duty tonight.

埃弗拉 今天晚上亚瑟值班。

George was on guard at the front gate last night.

乔治昨晚在大门口守卫。

The pack moves off, leaving the youngest member on guard.

狼群离开了，留下最年轻的站岗。

The conductor reminded passengers to keep on guard against the thief.

售票员提醒乘客谨防小偷。

Japan is still a country in recovery and still on guard.

日本仍然仍然是一个处于复苏及时刻需要保持警惕的国家。

To " watch their back" means to be prepared or on guard.

“to watch their back” 意指时刻准备着或保持警惕。

And today, NATO countries are on guard against moves by Russia.

今天，北约国家对俄罗斯的行动保持警惕。