Bad habits are not always easy to        ; it needs your determination.

--- Did you return the book you borrowed from Tom?--- Yes, I gave it to him ______ I saw him.

Everyone should learn something about first aid, because every second   in an emergency.

Every morning, week in, week out, from dawn to dusk , he ______ his place on the bend.

Teachers should _____ on their students the value of hard work.