数列$\frac{1}{1}$、$\frac{2}{1}$、$\frac{1}{2}$、$\frac{3}{1}$、$\frac{2}{2}$、$\frac{1}{3}$、$\frac{4}{1}$、$\frac{3}{2}$、$\frac{2}{3}$、$\frac{1}{4}$……依次排列到第$a_{2010}$项属于的范围是（    ）。

⑴What's this? ____                 A. He's my brother.

⑵How are you? ____              B. It's a pig.

⑶Who is he? ____                  C. Yes，I'm tall.

⑷Where is she? ____             D. I'm fine，thank you.

⑸Are you tall? ____               E. She's in the classroom.

⑹What can you do? ____      F. I can read.

(____) I'm looking out of the window.

(____) Some children are making a snowman.

(____) In this photo，we are in the mountains.

(____) The wind is blowing and the sun is shining.

(____) I am having a lovely time.

宋初采取“田制不立、不抑兼并”的土地政策，到了宋真宗时期变成了“百姓康乐，户口蕃庶，田野日辟”的景象。这表明宋朝的土地政策（    ）