This is a major problem throughout the world, as many cases remain concealed and unreported.

全世界仍有大量没有诊断或没有报道的病例，是一个严重的问题。

youdao

This is a major problem throughout the world, as many cases remain concealed and unreported.

全世界仍有大量没有诊断或没有报道的病例，是一个严重的问题。

youdao