beneficial

He hopes the new drug will prove beneficial to/for many people.他希望新药将有益于众人。

Regular exercise has many beneficial health effects.经常锻炼有益健康。

They have a relationship that is beneficial to/for both of them.他们保持着一种互惠互利的关系。

Some insects are harmful but others are beneficial.有些昆虫是害虫，而有些则是益虫。