causal agent造句怎麼寫

Could you tell me the main causal agents of plant diseases?

Crown rust is the common name both of a serious leaf-rust disease of oats and of the causal agent.

Symptoms and morphological characters of the causal agent of a newly recorded disease,the common corn rust in Xinjiang

[2] Vincent v. Lake Erie Transport was a superb decision, for there the court was careful to investigate the causal agent at work—in this case, the boat, which clearly slammed against the dock.