Some comparisons, like "is it between two numbers" starts to look quite complex using > and < signs. Consider looking for an empno between 3 and 5 inclusive:

select empno from employee
where empno<=5 and empno>=3

This can be rewritten using BETWEEN:

select empno from employee
where empno BETWEEN 3 and 5

Now find the course names (cname) in table COURSE where the cdate is between the start and end of 1988. A date looks like '01-Jan-1988', and you must always include the day, month, and year.