US President Donald Trump and Democratic Party challengers Joe Biden have faced off in their second and final presidential debate of the 2020 campaign. Sharing a stage at Belmont University in Nashville, in the US state of Tennessee, the two candidates clashed on China, Covid-19, race, climate change and immigration. The at times heated exchanges on October 22, 2020, also included barbs about Biden’s record as a lawmaker and former vice-president, as well as about Trump’s relationship with…