例句與造句

1. In 1918 he demonstrated that influenza was caused by a filterable agent that was in all probability a virus.
2. In 1898 Martinus Beijerinck repeated Ivanovski's work but went further and passed the " filterable agent " from plant to plant, found the action undiminished, and concluded it infectious replicating in the host and thus not a mere toxin.
3. It's difficult to find filterable agent in a sentence. 用filterable agent造句挺難的