智能手机最早出现在21世纪初。

Smartphones first ___appeared in the early 2000s.

关于选举的新闻出现在所有主要新闻网站上。

The news about the election ___appeared on every major news website.

新的共享单车服务出现在许多城区。

New bike-sharing services have ___appeared in many urban areas.