BEIJING — China expanded the scope of consumer trade-ins for home appliances and will give more subsidies for digital purchases this year, in efforts to revive sluggish domestic demand, an official policy document showed on Wednesday. Microwave ovens, water purifiers, dish-washing machines and rice cookers will be included in the trade-in scheme for home appliances this year, according to a document issued by the top state planner and the finance ministry. Cellphones, tablet computers, smart watches and bracelets under 6,000 yuan, or $815, could get 15% subsidies. The statement did not specify the total cost of the incentives, however, a