质量为m的跳水运动员进入水中后受到水的阻力而做减速运动,设水对他的阻力大小恒为F,那么在他减速下降高度为h的过程中,下列说法正确的是(g为当地的重力加速度)
It's nice to see you again.We each other since 2016.( )
won't see
haven't seen
don't see
didn't see
There some students on the playground.( )
is
have
has
are
have you felt like this?
Three days.( )
How long
How often
How much
How many
Must I finish the homework this morning?
( )
No,you mustn't
No,you can't
No,you may not
No,you needn't
My parents always ask me more vegetables and fruit.( )
eat
eating
to eat
eats