HSK 4
Lǎorén hé értóng de dǐkànglì jiào ruò, gèng róngyì gǎnmào.
The elderly and children have weaker immunity and are more prone to colds.
HSK 5
Jīngcháng duànliàn néng zēngqiáng dǐkànglì.
Regular exercise can strengthen one's immunity.
HSK 7-9
Yālì guò dà huì jiàngdī réntǐ de dǐkànglì.
Excessive stress can lower the body's resistance.
