Black Friday: lifetime access is on a special offer in the app, until November 30. Black Friday: special offer on lifetime access, until November 30. Download
염분계를 사용하여 바닷물의 염도를 측정했습니다.Yeombun-gye-reul sayonghayeo badatmul-ui yeomdo-reul cheugjeonghaessseubnida.I used a salinometer to measure the salinity of seawater.