Why is Australia's first match important to them ICC World Cup 2011?

Question

I am new with cricket, why is Australia's first match of ICC World Cup 2011 important to them?

Answer 1

Australia has already won one match and has gotten two points on the table by beating Zimbabwe. they would like to take these to four plus every team wants to get points early on the table with a good net run rate because by the end of the first round things might get really close in their group. Plus they are the defending champions