He doesn't like birthday cakes __________ birthday cards, but he likes parties.
A:and
B:or
C:too
D:with
如图所示,轻弹簧一端与墙相连,质量m=2kg的木块沿光滑水平面以V0=5m/s的初速度向左运动,当木块压缩弹簧后速度减为V=3m/s时弹簧的弹性势能是( )
Practice _______ perfect. ( )