China has given a boost to the battered European common currency during a visit to Beijing by top European Union leaders.Central Bank chief Zhou Xiaochuan said Wednesday that China has confidence in the euro and will continue to invest in bonds and other securities issued by EU countries. While he made no specific commitment, Zhou suggested China would work through the International Monetary Fund and two European bailout funds to help shore up the troubled currency. The remark reiterated a suggestion made the day before by Chinese Premier Wen Jiabao.