https://online2.tingclass.net/lesson/shi0529/10000/10090/foods16r.mp3
https://image.tingclass.net/statics/js/2012
A: What's the white stuff on your food?
B: It's sour cream. Want to try some?
A: I don't think so! It sounds gross.
B: It's not really sour.
A: Why is it called sour cream, then?
B: I think it's because they let the milk go sour to make it.
A: You're eating sour milk? Yuk!
B: Cheese is made in a similar way.
A: I thought cheese was made with bacteria.
B: Of course! Bacteria cause milk to go sour.
A: Dairy products are so strange.
B: Even so, I think they're delicious!