他姐姐长相相当普通，但性格极好。

His sister is quite ___plain, but she has a wonderful personality.

这位女演员常被选中扮演那位害羞、长相平平的邻家女孩。

The actress was often cast in the role of the shy, ___plain girl next door.

尽管他很富有，但众所周知他的外貌相当普通且不张扬。

Despite his wealth, he was known to be rather ___plain and unassuming in appearance.