17-20
COVID-19 is a highly contagious disease. Since it __17__ , the confirmed cases __18__ all over the world, which affected the way we work, learn, and travel. Worries and anxiety about COVID-19 could be__19__ . Some people are so worried that they have difficulty__20__ . Others have problems with sleep. Doctors indicate that we follow the government’s disease-prevention measures and then it’s not necessary to get troubled too much.
【題組】18.
(A) exploded
(B) has exploded
(C) have exploded
(D) had exploded