对许多人来说，减肥是一场艰苦的斗争。

Losing weight is ___an ___uphill ___struggle for many people.

全职照顾生病的亲人常常是一场艰苦的战斗。

Providing full-time care for a sick relative is often ___an ___uphill ___battle.

说服人们养成可持续的生活习惯可能是一场艰难的奋斗。

Convincing people to adopt sustainable habits can be ___an ___uphill ___struggle.