You're right you cannot use like to introduce an example in written English. But in spoken English it is extremely common. The goal of the listening section is to make sure that you can understand American English the way it's spoken in a day to day college situation. I don't know if you've lived in the US but I've been living in California for almost 4 years and I can tell you that people can't make a sentence without saying like at least 2 or 3 times. And don't get me started on the valley girl accent...
If you're interested check this link out:http://en.wikipedia.org/wiki/Valspeak
I can't believe wikipedia has an article on this lol
GMAT: 720 Q47 V41 / TOEFL iBT: 118