根据下周计划请说五句话。
On Monday Amy will read her books. On Tuesday she will play football. On Wednesday she will go simming. On Thursday she will watch tv. On Friday she will help her mother.
已知动员P过定点 M(−3,0) 且与圆N: (x−3)2+y2=16 相切,记动圆圆心P的轨迹为曲线C.
(Ⅰ)求曲线C的方程;
(Ⅱ)过点D(3,0)且斜率不为零的直线交曲线C于A,B两点,在x轴上是否存在定点Q,使得直线AQ,BQ的斜率之积为非零常数?若存在,求出定点的坐标;若不存在,请说明理由.
用性引诱剂诱杀农业害虫是利用( )
受精卵的形成和胚胎发育的主要场所是( )
关于食物中的水说法不正确的是( )