【单选题】以点 ( 3 ,-4 ) 为圆心,并且过点 (6 , 0 )的圆的方程为
A.
( x - 3 ) ² +( y + 4 ) ²=16
B.
( x - 3 ) ² +( y + 4 ) ²=25
C.
( x + 3 ) ² +( y - 4 ) ²=25
D.
( x + 3 ) ² +( y - 4 ) ²=16
【简答题】过圆x 2 +y 2 -x+y-2=0和x 2 +y 2 =5的交点,且圆心在直线3x+4y-1=0上的圆的方程为 .
【简答题】已知椭圆的中心在原点,焦点在y轴上,离心率为 ,且椭圆经过圆C:x 2 +y 2 ﹣3x+4y=0的圆心C. (1)求椭圆的标准方程; (2)设直线l:y=kx+1与椭圆交于A,B两点,点P(0, )且|PA|=|PB|,求直线的方程.
【简答题】小明今年8岁,爸爸今年32岁,今年爸爸的年龄是小明的几倍?小明的年龄是爸爸的几分之几?
【单选题】Why is a “full English breakfast” so called? a Be b Be c Be
A.
a Bcause it contains all the different types of food: bacon, eggs, sausages, etc.
B.
b Bcause it makes your stomach feel full.
C.
c Because you pay full price for it.
【单选题】按周期表排列,元素Be、C、Mg、Na的电负性大小顺序为( )
【判断题】双方实力相等,为了先下手为强,可以抢先报价,争取主动。
【单选题】Let p1 and p2 be pointer variables pointing to the same string, and c be character variables, then the following assignment statement that cannot be executed correctly is ( ).