kē / xué / jiā / zhèng / zài / cè / liáng / hú / pō / zhōng / de / shēng / wù / liàng / yǐ / píng / gū / shēng / tài / xì / tǒng / de / biàn / huà科学家正在测量湖泊中的生物量,以评估生态系统的变化。Scientists are measuring the biomass in the lake to assess changes in the ecosystem.