The USA is encouraging Americans to wear face masks. There has been a lot of talk about whether or not face masks are effective in helping slow down the spread of the Covid-19 coronavirus. The government is set (19) ______ Americans to use homemade face (20) ______ covering like cloth masks, bandanas and scarves. At first, the WHO and some health organizations recommended that people (21) ______ were not sick didn’t need to wear masks or cover their faces. However, it is now proved that face masks can work effectively. They point to countries like Singapore and South Korea, where people wear masks and reported infection (22) ______ are lower. 19. A. to release B. widen C. lengthen D. to encourage 20. A. covers B. covered C. covering D. to cover 21. A. which B. where C. why D. who 22. A. rates B. levels C. percentages D. scales