In this critical situation, we should help each other.
Cantonese
到咗紧要关头
到咗緊要關頭
dou3 zo2 gan2 jiu3 gwaan1 tau4
at a critical juncture
Examples (Wiktionary)
Mandarin
生死存亡的关头
生死存亡的關頭
shēng sǐ cún wáng de guān tóu
crucial juncture
Mandarin
现在，她就要走了，就在走的一刻，米籽心里却有点起毛，因为此刻的心情与她原先想像的有一点不同，她原以为憧憬了三年的流浪生涯一日迈步便将如“壮士一去不复返”般的慷慨，可真的将梦想兑换成现实的最后关头，却发现自己仍在作种种挣扎。
現在，她就要走了，就在走的一刻，米籽心裏卻有點起毛，因為此刻的心情與她原先想像的有一點不同，她原以為憧憬了三年的流浪生涯一日邁步便將如“壯士一去不復返”般的慷慨，可真的將夢想兑換成現實的最後關頭，卻發現自己仍在作種種掙扎。
xiàn zài ， tā jiù yào zǒu le ， jiù zài zǒu de yī kè ， mǐ zǐ xīn lǐ què yǒu diǎn qǐ máo ， yīn wèi cǐ kè de xīn qíng yǔ tā yuán xiān xiǎng xiàng de yǒu yī diǎn bù tóng ， tā yuán yǐ wèi chōng jǐng le sān nián de liú làng shēng yá yī rì mài bù biàn jiāng rú “ zhuàng shì yī qù bù fù fǎn ” bān de kāng kǎi ， kě zhēn de jiāng mèng xiǎng duì huàn chéng xiàn shí de zuì hòu guān tóu ， què fā xiàn zì jǐ réng zài zuò zhǒng zhǒng zhèng zhá ．
Now, she was about to leave. Right at the moment when she was leaving, Mizi got a little flustered in her heart because how she felt at this moment was different from how she originally imagined it. She had thought that once she stepped into the vagrant life she had been longing for for three years, she would have a big heart as "a warrior that goes without returning", but at the last critical point before her dream is exchanged for reality, she realized that she was still dealing with all sorts of struggles.
Mandarin
中国共产党在革命斗争中的伟大的历史成就，使得今天处在民族敌人侵入的紧急关头的中国有了救亡图存的条件。
中國共產黨在革命鬥爭中的偉大的歷史成就，使得今天處在民族敵人侵入的緊急關頭的中國有了救亡圖存的條件。
zhōng guó gòng chǎn dǎng zài gé mìng dòu zhēng zhōng de wěi dà de lì shǐ chéng jiù ， shǐ dé jīn tiān chǔ zài mín zú dí rén qīn rù de jǐn jí guān tóu de zhōng guó yǒu le jiù wáng tú cún de tiáo jiàn ．
The Party's great historic achievements in its revolutionary struggles have provided the prerequisite for the survival and salvation of China at this critical juncture when she is being invaded by a national enemy.