Experts are badly ________ that robots will completely take the place of human beings in the future.
After living with his grandparents in the countryside for ten years, the boy returned to the big city ____ his parents worked.
— ____ can I deal with such a situation? — Take ____ measure you think best.
____ it will do us harm or good remains to be seen.
The river, ____ are covered with trees, is very long.
He is rather difficult to make friends with, but his friendship, ____, is more true than any other.