“Did you go skating a lot last year?” I asked. Jen shook her head and looked at me. Finally she said， “On Thanksgiving， Mom and I always went to visit some friends who lived on a farm. I especially loved seeing their big turkeys.”

    Until then， I didn't think about how Jen felt. She had a new stepfather (继父) and stepbrother，and had a new town and home， too. Jen and her mom used to live near a lake where Dad and I went every summer， and she had to move up north with us. She had more changes than me.

    Jen seemed sad， so I was busy thinking of some ways to cheer her up on Thanksgiving. I told her my plan and she was excited. First we made a huge snowball， and then a small snowball. Then we built a wall behind the big snowball as a tail. Jen mixed some food coloring with water， saying， “We can spray (喷) colors on the tail.” Our snow turkey had a red， blue， green， and yellow tail. We were so busy that we didn't notice our parents come outside. Dad found a hat for the snow turkey， and Mom wrapped her scarf around its neck.

    “Thanks for cheering Jen up，” Mom said. “You're a good brother， and you always come up with great ideas.'' A happy feeling spread through me. I began to understand how much she cared about everyone in our new family.

如图所示，在平面直角坐标系中，菱形MNPO的顶点P的坐标是（3，4），则顶点M、N的坐标分别是（　　）

①函数 $y=sin\left(2x+\frac{\pi }{3}\right)$ 的单调减区间为 $k\pi +\frac{\pi }{12}，k\pi +\frac{7\pi }{12}，k\in Z$ ；

②函数 $y=\sqrt{3}cos2x-sin2x$ 图象的一个对称中心为 $\left(\frac{\pi }{6}，0\right)$ ；

③函数y=cosx的图象可由函数 $y=sin\left(x+\frac{\pi }{4}\right)$ 的图象向右平移 $\frac{\pi }{4}$ 个单位得到；

④若方程 $sin\left(2x+\frac{\pi }{3}\right)-a=0$ 在区间 $0，\frac{\pi }{2}$ 上有两个不同的实数解x₁，x₂，则 $x_1+x_2=\frac{\pi }{6}$ ．

其中正确命题的序号为____．

填入下列句子空白处的词语恰当的一项是（    ）

①从这一刻起，中国恢复对香港行使主权，英国在香港长达156年的殖民统治宣告____________。

②在车轮扬起的滚滚黄尘里，在一片____________恼怒的喇叭声里，那一片清阴不再有用处。

③____________你没有刻苦钻研的精神，____________坐着，也可能是小和尚念经，有口无心。