[译] 环磷酰胺对癌症有效。
[误] Cyclophosphamide is effective on cancer.

[正] Cyclophosphamide is effective against cancer.
[注] 名词 effect 之后常用介词 on, 如: Did the medicine have any effect on anorexia? 那种药对食欲不振有效吗？但是，形容词 effective 则要求用介词 against, 又如: Furacilin is effective against the ulcers. 呋喃西林可抗溃疡。