U.S., China tiptoe around holes in new trade agreement

WASHINGTON (Reuters) - The United States and China signed an initial trade deal on Wednesday that will roll back some tariffs and boost Chinese purchases of U.S. products, defusing an 18-month row between the world's two largest economies but leaving a number of sore spots unresolved.Beijing and Washington touted the "Phase 1" agreement as a step forward after months of start-stop talks, and investors greeted the news with relief. But there also was scepticism the U.S.-Sino trade relationship..