How to merge 2 MySQL tables and output data to table?

Question

MySQL

There are two tables users (id, username, FIO, uchebnaya_group) and rubezhnii_kontrol (this is where teachers grade students) (iduser, rk1, rk2, itog, sr_ball).
It is necessary to create a query that will display all users of a particular study group and the grade set by the teacher in the rubezhnii_kontrol table

Table

Request:

$query =    "SELECT 
            surname,
            fullname,
            otchestvo
            FROM users
            WHERE nomber=237";
$res = mysqli_query($dbh, $query);

How to display the grades that the teacher gave to a particular user?

Table