Asian shares and commodity currencies dropped on Thursday as investor concerns about a slowing Chinese economy eclipsed optimism over the U.S. MSCI’s broadest index of Asia-Pacific shares outside Japan fell 0.3 percent, led by declines in Australia and China, under pressure from concerns over slower growth the world’s second-largest economy. The Australian dollar flirted with a four-year low of $0.8606 hit on Wednesday while the Canadian dollar stood near five-year lows of C$1.1466 to the U.S.