OTTAWA — Canada posted a merchandise trade deficit of $3.4 billion in May as imports of unwrought silver soared and lower oil prices weighed on exports, Statistics Canada said Thursday. The result was the largest deficit since October 2020 and compared with a revised surplus of $894 million in April. TD Bank economist Marc Ercolao said that while the report appeared to be following a broader downtrend in May, export activity in crude oil is expected to rebound in June as oil production in Albert