Zhè yī dìqū de dàxióngmāo zhǒngqún zhèngzài zhújiàn huīfù.
The giant panda population in this region is gradually recovering.
Kēxuéjiā yánjiū zhǒngqún de shùliàng biànhuà yǐ liǎojiě shēngtài xìtǒng.
Scientists study population changes to understand ecosystems.
Guòdù bǔliè dǎozhì gāi yúlèi zhǒngqún jíjù jiǎnshǎo.
Overhunting has caused a sharp decline in the fish population.
