联通公司手机话费收费有A套餐（月租费15元，通话费每分钟0.1元）和B套餐（月租费0元，通话费每分钟0.15元）两种．设A套餐每月话费为y1（元），B套餐每月话费为y2（元），月通话时间为x分钟．
徐州自古乃兵家必争之地，历史上多次重大战役都围绕着徐州展开。其中，抗日战争和解放战争时期与此有关的重大战役分别是（ ）
阅读，判断句子正（T）误（F）。
Dalong is ten. He likes swimming. This is his father, He likes basketball. This is his mother. She likes table tennis and skiping. This is his sister, Lanlan, She likes skipping and swimming. She doesn't like football.
是曲线
上一点，且在点
平行，则点
