Even scalpers try to profit by trading reservation vouchers, one of the most sought-after items in the Expo Garden.

Yet Qian is accustomed to the pressure and his job is mainly about taking care of the more than 50,000 daily visitors.

"One of the most important pieces of 'homework' after the pavilion closes each day is analyzing visitors' complaints and seeking solutions," Qian said.

For instance, drinking water faucets were added after visitors complained it was hard to find drinking water in the pavilion.

Qian also came up with the idea of a "gathering point" in the structure, which helps missing group members find each other.

It doesn't require a lot of wisdom, Qian said. "But you have to have a heart for visitors. I thought about solutions and improvements for a better visiting experience even in my dreams."

Qian said he was glad to see the design and operation of the China Pavilion meet the public's expectations.

"Surveys show that the China Pavilion is one of the most popular structures at the Expo," Qian said.

One impressive comment was from a blind visitor, who said the power of China could be felt by listening to the audio guide at the pavilion.

Qian also defended the Expo against those who questioned its necessity in the era of the Internet when people can easily grab information from the Web.

"It's like the difference between a pocketbook and a movie," Qian said. "You cannot get the knowledge in such a real way and by combining many forms of art and technology without the Expo."

He cited the scroll Along the River During the Qingming Festival, the centerpiece of the China Pavilion, as an example.

The modern version of the giant painting by Song Dynasty artist Zhang Zeduan (AD 1085-1145) was projected as a three-dimensional image on a digital screen measuring 100 meters by 6 meters.

"It's something you can't appreciate in a textbook or on the Internet," Qian said.