People lined up on Wednesday to visit a major exhibition in Beijing commemorating the 40th anniversary of China's reform and opening-up.

The exhibition opened at the National Museum of China on Tuesday and showcases a wide range of sectors, including the economy, technology, environment, culture and education. It presents the country's 40 years of development and the changes in people's lives.

According to a volunteer at the museum, many visitors flooded into the building as soon as the exhibition opened at 8:30 am. Less than an hour later, the building was teeming with people, and many waited in long lines outside.

There were more than 31,000 visitors on Wednesday, the museum said.

Zhang Zhiqiang, a 35-year-old teacher from Zhengzhou, Henan province, with his wife and their 3-year-old son, canceled their plan to visit the Summer Palace after they saw the opening ceremony of the exhibition on television.

"This is a great opportunity. Although my son is too little to learn, I still wanted him to know that he was born in a great country at a great time," Zhang said.

Themed "Adhering to and developing socialism with Chinese characteristics", the exhibition has six sections showcasing the history, accomplishments, and experience of reform and opening-up, and the strategic decisions and plans made by the CPC Central Committee with Xi Jinping at the core since the 18th CPC National Congress.

"I hadn't seen any of these achievements before I visited China - the curved skyscrapers, the bullet trains, the subways, its friendly people and so many amazing things. When I sent back photos to my family, they asked if I am visiting some country in Europe," said Alan Smith, a 60-year-old Canadian.

Last week, Smith and his wife visited Shanghai, where reform and opening-up has brought tremendous changes. He said he saw a city of the future.

"I thought metropolises like Shanghai or Beijing were just exceptions and don't represent the development of the entire country. But the exhibition shows me the other side of China and helps me to know a real China," he said.

The exhibition uses photos, text and videos of significant events and decisions over the course of reform and opening-up, as well as models of the country's Long March rocket series and the Tiangong space station to show visitors the trajectory China has followed to stand up, grown rich and become strong.

"I'm thrilled to see the achievements we've made in aerospace technology in the 40 years. For example, Tiangong is a great step forward in China's space exploration and a milestone of China's development in the area," said Zhou Rixin, who used to work for China Space News. The 78-year-old said he was proud of all the accomplishments and hoped to see more breakthroughs in the aerospace industry.

The exhibition will run through the end of December.