__ many times, but she still didn't know how to do it.
You may find it _______ that Charlie was taught to sing as soon as he could speak.
Since then, finding ways to grow more peanuts ______ his life goal.
______ with new scientific farming methods, they have been able to use less farmland thanin the past.
Only after I read the book _______ why she devoted all her life to medical work forChinese women and children.
It is ______ to improve the working conditions for the construction workers.