Answer:
1: Never are students allowed to use dictionaries in the test.
2: Never could Mary have given you any money.
3: No sooner than he came home, the problem intensified.
4: Only occasionally does Sharon talk to me these days.
5: Under no circumstances are you to talk to him about any issue.
Explanation:
The activities in which human beings are engaged in different kinds of economic works to generate income are called economic activities.
or in simple words
Any work from which we can generate income are called economic activities
hope this helps you
c or the 3rd option however u would like to put it