已知二次函数y=-2x2+4x+k(其中k为常数),分别取x1=-0.99;x2=0.98;x3=0.99,那么对应的函数值为y1、y2、y3中,最大的为( )
A:y3
B:y2
C:y1
D:不能确定,与k的取值有关
钟鼓乐之 ____
All the children like Mr. White very much because he often makes them _______.