他们正在调查肥胖症可能由病毒引起的假说。

They are investigating the ___hypothesis that obesity may be caused by a virus.

现有数据并不支持这一初步假设。

The available data does not back up this initial ___hypothesis.

研究者的假设必须通过严格的实验来检验。

A researcher's ___hypothesis must be tested through rigorous experimentation.