Canada has entered a second wave of the coronavirus pandemic, Prime Minister Justin Trudeau said on Wednesday, warning that the country was on the brink of a surge if people did not follow public health guidelines.In a rare national address, Trudeau said the country "is at a crossroads" as a second wave emerges in four large provinces, adding that the government would do whatever it took to help the country recover from the pandemic."We're on the brink of a fall that could be much worse than the spring," he said.Canada's COVID-19 cases have spiked in recent days, with an average of 1,123 new cases reported daily over the past week, compared with a daily average of 380 cases in mid-August."We have the power to get this second wave under.