Combine these pairs of sentences as in the example. Example: The ...

Viktor

Combine these pairs of sentences as in the example.
Example: The services are useful. The workers provide the services. => The services which the workers provide are useful/
 
a. The goods are essential. They need the goods.
b. The schools and hospitals are essential. The provide the schools and hospitals.
c. The goods are valuable. He buys the goods.
d. The money buys essential commodities. People earn this money.
e. The goods and services are very useful. People produce these goods and services.
f. The work is called economic activity. We do this work. 
g. The work provide them with money. People do this work.
h. The economic activities make up the economic system. People undertake these economic activites.