Workers examine the parts of truck doors in China National Heavy Duty Truck Group Co., Ltd. (Sinotruk Group) in Jinan City, capital of east China's Shandong province, July 5, 2011. Sinotruk Group, China's leading heavy-truck manufacturer, manufactured China's first heavy-duty truck "Huanghe" (Yellow River in Chinese language) in 1960. In 2010, Sinotruk Group exported 14,500 vehicles to other countries with value totaling 400 million US dollars. During the first half of this year, the exports almost doubled over the same period of last year to top 10,000 vehicles. Its high-end HOWO-A7 model heavy duty truck has applied for over 130 latest patents, an evidence of the maker's effort to strengthen self-renovation. (Xinhua/Xu Suhui)