$1.$ Complete the missing values in the following SQL statement that would generate the report:

SELECT $[$A$],$ Customer$\_$No$,$ Customer$\_$Name, $[$B$]$ AS Sale$\_$Total

FROM $[$C$]$ LEFT JOIN Sales ON Customers.Customer$\_$No$=$Sales.$[$D$]$

$2.$ Write a SQL query that answers the following questions:

A$.$ What was the total amount of sales $($in dollars$)$ from $2020?$

B$.$ Which customer has the highest credit limit$?$

C$.$ Which salespeople $($identify by number$)$ had the most sales $($number of invoices$)$ in Dece