Chest pains can be a  warning ____of heart problems.

Do you have any ________on forbidding drunk driving ?

Electricity, like other forms of ______, has greatly increased in price in recent years. 

Her boss expressed his unsatisfaction with ________she has made in the development of market.

. It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.