A train runs through a field of flowers near the Juyongguan Pass of the Great Wall in Beijing, capital of China, March 28, 2016.[Photo/Xinhua]

A train runs through a field of flowers near the Juyongguan Pass of the Great Wall in Beijing, capital of China, March 28, 2016.[Photo/Xinhua]

A train runs through a field of flowers near the Juyongguan Pass of the Great Wall in Beijing, capital of China, March 28, 2016.[Photo/Xinhua]

Trains run through a field of flowers near the Juyongguan Pass of the Great Wall in Beijing, capital of China, March 28, 2016.[Photo/Xinhua]

A train runs through a field of flowers near the Juyongguan Pass of the Great Wall in Beijing, capital of China, March 28, 2016.[Photo/Xinhua]

A train runs through a field of flowers near the Juyongguan Pass of the Great Wall in Beijing, capital of China, March 28, 2016.[Photo/Xinhua]