Yesterday Lucy told us such good that we are all amazed at it.
A:news
B:ideas
C:suggestion
D:answer
一Did you____(吃)any fresh food ?
一Yes. I did.
下列各式中①a;②b+1;③a2;④a2+3;⑤x2-1;⑥x2+2x+1,一定是二次根式的有( )个.
本初子午线是指( )
你认为以下行为属于男女同学恰当交往的是( )