where 3 <= ALL ( select count(*) from Depends D where D.eno=E.eno) （答案2）
select E.ename, E.ename from Employees E,
(select eno, count(*) as d_num from Depends group by eno) D where E.eno = D.eno and D.d_num >= 3
（答案3）
Select E.eno, E.ename
from Employees E, Depends D1, Depends D2, Depends D3 Where E.eno = D1. eno and E. eno = D2. eno and E.eno=D3.eno
and D1.name<>D2.name and D1.name<>D3.name and D2.name<>D3.name
（答案4）
select E.eno, E.ename
from Employees E, Depends D where E.eno = D. eno group by E.eno, E.ename having count(*) >= 3
