补全对话 从每题A、B、C、D中, 选出一个能够填入对话空白处的最佳选项。
A: Hey, John.
B: Hi, Michael.
A:1
B: I’m reading a book.
A: 2I have got the latest movie video. Let's watch it together.
B: Great. Where is your house?
A:3. There is a small bookstore at the crossing. I'll meet you there.
B: Oh, OK.4
A: What about 2 pm?
B: OK. By the way, I haven't finished my homework yet and I have some problems with it.
A: 5We can do it together then.

2017年4月1日，中共中央、国务院决定设立国家级新区——         ，对于集中疏解北京非首都功能，具有重大现实意义和深远历史意义。（    ）

已知数列$\left\{a_n\right\}$满足$a_1=0$，$a_{n+1}=a_n+2\sqrt{a_n+1}+1$，则$a_{13}=$(      )