曝气生物滤池反冲洗系统由哪些组成？其目的是什么？
Which two are true about has-a and is-a relationships？（） [" Inheritance represents an is-a relationship."," Inheritance represents a has-a relationship."," Interfaces must be used when creating a has-a relationship."," Instance variables can be used when creating a has-a relationship."]
根据动机的归因理论，在能力高低、努力程度和身心状态三种因素中，属于可控的内在因素是（） ["能力高低","努力程度","身心状态","以上均不是"]
对《卡门》中的人物特点描述错误的是（） ["#61623;A、复杂","B、真实","C、平面","D、可信"]
你认为这本书是有价值的，而别人却认这为它毫无用处，原因在于（） ["缺乏沟通","相互之间有矛盾","过分自信","个体价值观的差异"]
简述烟草打顶抹杈的作用与方法。
