OTTAWA — An Ontario company that is being threatened by a massive retroactive tax bill because its golf carts were categorized by Ottawa as electric vehicles (EVs) isn’t alone. At least one other Canadian company that also has its motorized push carts manufactured in China says it has also received a tax bill from Canada Border Services Agency (CBSA) that is large enough to threaten its business. Hanson Xie, director of operations of Markham, Ont.-based Axglo Inc., says the federal government has told his company to pay about $500,000 in back taxes for the importation of its carts....