A passage is given with 5 questions following it. Read the passage carefully and choose the best answer to each question out of the four alternatives. 

There is consistent, strong evidence to prove that the SARS-CoV-2 virus, behind the COVID19 pandemic, is predominantly transmitted through the air, according to a new assessment published on Friday in The Lancet journal. The analysis by six experts from the UK, the US and Canada says public health measures fail to treat the virus as predominantly the airborne route leave people unprotected and allow the virus to spread. Although some studies in the past have suggested that COVID-19 may spread through air, overall scientific literature on the subject has been inconclusive. In July last year, over 200 scientists from 32 nations wrote to the WHO, saying there is evidence that the coronavirus is airborne, and even smaller particles can infect people. “The evidence supporting airborne transmission is overwhelming, and evidence supporting large droplet transmission is almost non-existent,” said Jose-Luis Jimenez, from the University of Colorado Boulder in the US. “It is urgent that the World Health Organization and other public health agencies adapt their description of transmission to the scientific evidence so that the focus of mitigation is put on reducing airborne transmission,” Jimenez said. Studies have confirmed these events cannot be adequately explained by close contact or touching shared surfaces or objects, the researchers said in their assessment. 

They noted that transmission rates of SARS-CoV-2 are much higher indoors than outdoors, and transmission is greatly reduced by indoor ventilation. The team cited previous studies estimating that silent - asymptomatic or presymptomatic - transmission of SARS-CoV-2 from people who are not coughing or sneezing accounts for at least 40 per cent of all transmission.