liǎng / jiā / gōng / sī / hù / xiāng / yī / lài / rèn / hé / yì / fāng / dǎo / xià / dōu / huì / chún / wáng / chǐ / hán

两家公司互相依赖，任何一方倒下都会唇亡齿寒。

The two companies depend on each other, so either one falling would harm the other.