Thousands of secondary school pupils across Hong Kong joined anti-government protests on the first day of school on September 2, 2019.  Organisers estimate as many as 10,000 students from 200 schools took part in the strike to voice anger about the government's now-shelved extradition bill.  Thousands of students and some alumni were expected to head to the city centre for an anti-government rally.  Meanwhile, Hong Kong police have been patrolling dozens of MTR stations across the city to…