HSK 3
Zài lǎoshī de bāngzhù zhīxià, tā jìnbù hěnkuài.
Under the teacher's guidance, he improved quickly.
HSK 3
Zài yālì zhīxià, tā zuòchū le cuòwù de juédìng.
Under pressure, he made the wrong decision.
HSK 4
Bǐjiào zhīxià, zhège fāng'àn gèng hǎo.
By comparison, this plan is better.