根据下列句意,用括号内所给英语单词的适当形式填空
It'sdifficultforthekid_____(carry)theheavybox.
Ifyouhaveany_____(difficulty),callmeatonce.
Nowthereisless_____(live)spaceforeachfamilythanbefore.
One_____(five)ofthewaterisfromtheriver
60percentofthestudentsinourclass______(be)interestedinthemovie.