SHANGHAI (AFP) - China said it was "extremely puzzled" by Washington's complaint to the World Trade Organization over its tax system for domestic chip makers but said it is willing to work with the United States to resolve the dispute. The Ministry of Commerce has yet to receive any official documentation but said it was in touch with its US trade counterparts in hopes of finding a solution. "China has had several rounds of negotiations with the US on this issue and we have already made progress," commerce ministry spokesman Chong Quan said in a statement. He added, however, that...