实验室要求提供尿液样本进行分析。

The laboratory requested a urine ___sample for analysis.

采集血液样本后，医生将它们送到实验室。

After collecting the blood ___samples, the doctor sent them to the lab.

土壤样本可以揭示许多环境条件信息。

A soil ___sample can reveal a lot about environmental conditions.