设n_A为阿伏加德罗常数的值。下列说法正确的是( )

A．1L1mol·L^－1的NaClO 溶液中含有ClO^－的数目为n_A

B．1mol的羟基与1 mol的氢氧根离子所含电子数均为9n_A

C．标准状况下，22．4L盐酸含有n_A个HCl分子

D．标准状况下，6．72L NO₂与水充分反应转移的电子数目为0．2n_A

用合适的句子补全对话

Salesman : Can I help you,Sir?

Mr. Ross : May I see a hat , please?

Salesman :   1   Mr. Ross : I'm sorry,l don't know.

Salevman: I'll measure you…You take size 6.  2   

Mr. Boss : Brown , please.

Salesman: Here are some nice brown hats.  3   It's a very good one.

Mr. Ross : Yes,l like this one. It goes very well with my coat.  4   Salesman : It's  $9. 95. Do you want me to put it in a box?

Mr. Ross:     5  .   Thanks a lot.Salesman : It's a pleasure.