#1
select count(distinct emp_no)
from dept_emp
where to_date>=curdate();


#3
SELECT employees.emp_no, salaries.to_date, salaries.salary, employees.first_name , employees.last_name
FROM employees
INNER JOIN salaries ON employees.emp_no = salaries.emp_no
WHERE to_date>curdate() order by salary desc limit 10;

#4


SELECT employees.emp_no, employees.first_name , employees.last_name
FROM  dept_manager
Left JOIN employees ON employees.emp_no = dept_manager.emp_no
WHERE to_date>curdate() ;