leading word I know (that)doctores work very hard √I believe (that) the world will over come COVID- 19 soon. I think (that)all the Chinese are heroes in fighting COVID-19 that-clauses: know/believe/think.+(that)+陈述句 Ve can leave out(省略)“that”in an object clause.ü I know (that) doctores work very hard. ü I believe (that) the world will over come COVID- 19 soon. ü I think (that) all the Chinese are heroes in fighting COVID-19. that-clauses: know/believe/think... + (that) + 陈述句 leading word We can leave out (省略) “that” in an object clause