If...recent barriers to China's oil industry ambitions are any indication, China's approach to Africa will get more difficult and may require revision...Miners and their families in Zambia and across the border into Congo's mineral-rich southeastern province of Katanga have rioted over the appalling safety and slave-labour working conditions in Chinese-run mines. People on the streets in Zimbabwe...rail at the takeover of locally owned retail businesses...Another cause of friction is Chinese companies buying or acquiring vast tracts of agricultural land...and then importing Chinese labour...to work the farms. [refers to CNOOC, Sinopec, Sonangol, Venerex]