<image>The image below shows the sales figures of Want Want Food Company in the first half of 2008:

(1) The sales amount was the highest in quarter (____), which was (____) ten thousand yuan. _____
(2) The average monthly sales in the second quarter were (____) ten thousand yuan. _____
(3) The month with the lowest sales figure had (____) ten thousand yuan less than the month with the highest sales figure.
(4) The total revenue for this half year was (____) ten thousand yuan.