a. not producing an intended effect
s. lacking in power or forcefulness
s. lacking the ability or skill to perform effectively; inadequate
a. 无效的
[法] 失效的, 无效的, 效率低的
1. The medication was ineffective in treating her cold.
这种药物对治疗她的感冒无效。
2. His efforts to fix the car were ineffective, so he called a mechanic.
他修车的努力没有效果，所以他叫了个修车工。
3. The training program was ineffective and did not improve our skills.
这个培训项目无效，没有提高我们的技能。