阅读材料，回答问题

材料一：当前，中国经济和世界经济高度关联。我国具有了资金、技术、产能、经验等发展优势，需要更大范围、更高水平、更深层次的区域合作，共同分享中国改革发展红利、中国发展的经验和教训。

材料二：40多年来，我国人口过快增长的势头得到了有效控制。老龄化绝对人口不断增加、人口分布失衡问题越来越凸显。因此，国家逐步完善政策，促进人口长期均衡发展。

材料三：北京最大优势是首都优势、智力密集、全国交通枢纽、市场容量大，是政治、文化、国际交流中心；天津最大优势在于港口优势、制造业优势、科技教育优势；河北最大优势在于资源优势和重化工业优势。扬长避短，促进京津冀区域协调发展。

材料四：在今年的政府工作报告中，***指出加快改善生态环境特别是空气质量，市人民群众的迫切愿望，必须科学施策、标本兼治，坚决打好蓝天保卫战。

    Today was Emily's birthday. She was happy and went home quickly after school.

    “You have to look for your gift on your own，” her sister said. “Here is the first clue(线索).” She gave Emily a piece of paper.

    Emily opened the note and read， “Clue Number 1： Look inside the car.” She found a bone(骨头) for dogs and another note in the car.

    “Clue Number 2： Look at the swing.” On the swing there was a bag of dog food with the third note.

    Again she quickly read the note， “Clue Number 3： Look into the house.” Emily found a dog's leash(皮带) there.

    The note on the leash asked her to go outside. There she saw a beautiful red doghouse.

    Before she got there， a black puppy ran up to her. It had a note on it. The note said， “Happy Birthday， Emily.”

    “Oh， such a cute dog!” she cried. She was so happy. “I will name her Happy， because she made me so happy today，” Emily said.