5.
Chuck: She told you about our little run-in last night.
Nate: You told me you'd back off.

run-in: 偶遇
back off: 靠邊站，不管這件事，和leave it alone很像，但是語氣更加嚴(yán)厲。

6.
Blair: I thought if I proved the North Caro liar was cheating with his ex, that would be it, but she fell for his business meeting excuse-- monkey business, more likely.
Chuck: With Serena and Poppy both fighting over the banana.
Blair: I'm really worried, Chuck. You know how Serena is. She gets in over her head. We need to expose this two-timer for what he is.

fall for: to be deceived or swindled by，對謊言深信不疑
monkey business: silly, mischievous, or deceitful acts or behavior. 騙人的把戲
get in: to become or cause to become involved 陷入
two-timer: to be unfaithful to (a spouse or lover), double-cross，辟腿的人，同時(shí)有兩個(gè)女(男)朋友

7.

Poppy: What an idiot I am! Using my connections for your company?
Gabrielle: Poppy, it is not like that. You know it's not.?

connections: 人際關(guān)系，也可以用network。networking這個(gè)單詞也可以做動詞用，表示“搞人際關(guān)系，經(jīng)營人際關(guān)系”

8.
Jenny: Dad, my whole life, you said that I could do anything if I was willing to risk falling flat on my face. So why doesn’t that same advice apply to you? Right?
Rufus: Good point.?

fall flat (on one’s face): to fail to achieve a desired effect達(dá)不到預(yù)期效果, 完全失敗
good point: 有道理

9.
Chuck: So I heard you, uh, first met Serena on one of her infamous nights with Georgina. You know, I've always wanted to know what happened. It must be quite the story.?

infamous: 臭名昭著的，聲名狼藉的
It must be quite the story: 肯定大有文章，肯定有猛料?

10.
Lily: Well, this is just the sort of thing that some of us at bass have been pushing for. Doing well by doing good.
Gabrielle: Yes. But the only thing is there's a ticking clock. Some of the major internet corporations are pushing to do a similar thing. If we act now, we block them completely and we make at least triple our investment.