More than 20 people,______to have started bushfires in Australia's New South Wales,have been caught by the police.A.believe B.are believed C.believed D.believing为什么are要省略，是因为非谓语的原因吗

More than 20 people,______to have started bushfires in Australia's New South Wales,have been caught by the police.A.believe B.are believed C.believed D.believing为什么are要省略，是因为非谓语的原因吗
More than 20 people,______to have started bushfires in Australia's New South Wales,have been caught by the police.A.believe B.are believed C.believed D.believing
为什么are要省略，是因为非谓语的原因吗

More than 20 people,______to have started bushfires in Australia's New South Wales,have been caught by the police.A.believe B.are believed C.believed D.believing为什么are要省略，是因为非谓语的原因吗
选C.
1, More than 20 people have been caught by the police.
2, More than 20 people are believed to have started bushfires in Australia's New South Wales.
主语相同,1句为主句, 2句作为修饰主句的主语More than 20 people 时,用表示被形式的-ed且要去掉are.

选C。 believed to have started bushfires in Australia's New South Wales作people的后置定语，表示被认为引起了林区大火的人。该句的主干是people have been caught。

c