3 sentences

1. 即无外援，我们也必须坚守阵地。

   jí wú wài​yuán, wǒ​men yě bì​xū jiān​shǒu zhèn​dì.

   Even without outside help, we must hold our ground.

   Source: Dong Chinese Dictionary

2. 由于遭受了严重的旱灾，该国正在寻求国际外援。

   yóu​yú zāo​shòu le yán​zhòng de hàn​zāi, gāi guó zhèng​zài xún​qiú guó​jì wài​yuán.

   Due to the severe drought, the country is seeking international aid.

   Source: Dong Chinese Dictionary

3. 本赛季，这支篮球队引进了几名实力强劲的外援。

   běn sài​jì, zhè zhī lán​qiú​duì yǐn​jìn le jǐ míng shí​lì qiáng​jìng de wài​yuán.

   This season, the basketball team has brought in several strong foreign players.

   Source: Dong Chinese Dictionary