So, penguin parents must always be on guard.

此，企鹅父母必须时刻保持警惕。

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。

There is a soldier on guard all the time.

一直都有士兵在站岗。

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。

You can do what you will, but I must remain on guard.

你有事可随尊便，我必须在这里守候。

While the Gestapo searched for leads, the White Rose were constantly on guard.

在盖世太保搜寻线索的同时，“白玫瑰”一直备状态。

One tree swallow was in the nest and the other on guard outside.

一只树燕子在窝里，另一只在外面站岗。

Major ports on India's east coast are on guard against an incoming storm.

印度东海岸的主要港口对即将到来的风暴保持警惕。

33 Be on guard! Be alert! You do not know when that time will come.

33 你们要谨慎、儆醒祈祷、为你们不晓得那日期几时来到。

Like other animals, we are on guard until we know it is safe to relax.

跟动物一样，我们会保持警觉直至知道安全的时候才放松。

The female on guard has no choice but to move on as the boys feast.

警惕的母驼鸟除了离开外没有其它选择，留下两只小公狮在那里大快朵颐。

Be on guard for symptoms such as chest congestion, extreme cough or pain in the stomach.

如果出现胸闷、严重咳嗽或胃部疼痛等症状，那就需要警惕了。