Directions ： Analyze the following chart and write in no less than 100 words a passage entitled “ The Sales of Products X，Y and Z over the Last 12 Months”. You may refer to the clues given below.
Describe the trend of sales of the three products over the 12 months.
Compare the three products in sales in terms of change by asking：
Which product shows the greatest increase over the 12 months?
Which product falls sharply first and then goes up steadily afterwards?
Which product maintains almost the same level until September and then shows some change?