China's economy gathered steam in the first quarter, as robust exports growth offset tepid domestic demand, though the Iran war-fueled energy shock clouds growth outlook, threatening global demand. Gross domestic product grew 5% in the three months to March, data from the National Statistics Bureau showed Thursday, accelerating from 4.5% in the prior quarter and exceeding economists' forecast for a 4.8% growth in a Reuters poll. Beijing had lowered its growth target this year to a range of 4.5%