看图写答句。

1.-What is Christmas?

   -Christmas is a s____ h____.

2.-What is Lynn going to do?

   -She's g____ t____ o____ her gift.

3.-What is Li Ming doing ?

   -He's g____ a g____ to them.

4.-What are they putting on the Christmas tree ?

   -They're putting on the l____.

5.-What's this?

   -It’s a g ____.M____ Christmas!

在一定体积某浓度的Ba(NO₃)₂溶液中，逐滴加入pH=1的稀硫酸至溶液中的Ba^2＋恰好完全沉淀时，测得溶液pH=2，若忽略两溶液混合时的体积变化，则稀硫酸的体积与Ba(NO₃)₂溶液的体积比是

A．10∶1

B．1∶10

C．9∶1

D．1∶9