听力原文： Google and Sun Microsystems are joining forces and together they are going to challenge Microsoft's dominance of the desktop computer market. Google is going to be offering Sun's Open-Office software on its website and Sun will include the Google Toolbar for web searches as an option when people download Sun's Java program. Company spokesmen have declined to name the financial figures behind the deal but Google's Chief Executive said it was significant. Microsoft is feeling pressure as technology firms offer cheaper or even free rival products. Well Sun's Chief Executive Officer explained at a press conference in California yesterday the logic behind the tie-up: 'This is a big deal it's pretty exciting, and I think it is a fairly natural partnership here so it shouldn't surprise a lot of people that we are back up on stage, you know, brings the free internet services and search company of all time, Google up here with the number one player and the open source free and open software space.' In which domain will Google and Sun cooperate to challenge Microsoft?