What's the Point of Chewing Gum?

Being an American, Donna wants to learn more about the Chinese. She's talking to her Chinese friend, Jeff.

D: Hi, Jeff! What's up?
J: Nothing much. What about you?
D: Same as usual. Here, have a stick of gum.
J: No, thanks. I'll stick to my own brand.
D: And what brand's that?
J: Actually it's not gum. I eat raw garlic instead. Want a piece?
D: No way! So that's where the stinky smell is coming from.
J: Hey! Watch your tongue, ok? Garlic kills germs. It's good for you.
D: Says who?
J: Well, according to…
D: Never mind. Please stop talking. Your breath stinks. I'm out of here.
J: Boy! These Americans don't know what's good for them. Besides, what's the point of chewing gum anyway?

onion 洋葱
What's the point of... = What's the use of... ...有什么意义呢?
There is no use in talking to Peter, he is stubborn.
a stick of gum = a piece of gum a pack of gum 一包 gum不可数 Would you care for a stick of gum?
the Chinese the English
Traveling can help you learn more about the world. He is well-traveled. well-educated
What's up? 极为口语的用法 answer: Nothing much. or Nothing special.
same as usual = nothing much
Stick the stamp on the envelope. 粘 stick to 坚持 I am loyal to the lawer. 忠实的
brand-new 全新的
stinky tofu 臭豆腐 beancuid 豆腐(已少用)
watch your tongue = watch your language 注意用词
bacteria 一类细菌 germ 总称 viruses滤过性病毒
Says who? 谁说的?(表怀疑)
boy! 表惊讶