14. Although I may not be doing a bang-up job yet, it beats having a woman of your reputation at the helm.

bang-up: very good
it beats: 那也总好过…
at the helm: 掌舵，掌权

15. Serena: I know that look. You're up to no good.
Blair: Good is subjective, and if you don't believe me, you can look it up.
Serena: You want to get Rachel back for the grade she gave you.
Penelope: A new teacher's like a child. It has to be taught.
Hazel: And spanked.

You're up to no good: 你又不怀好心，搞阴谋诡计了
get back for: 打击报复
spank: 打屁股

16. Eric: In our world, people say one thing, but they expect something else. If you can hold your own, it'll go a long way with my mom and her friends.

hold your own: 做你自己
go a long way with: 对…有效，大有帮助

17. Gossip Girl:Spotted, B hot for teacher.

make it hot for: to make things uncomfortable or dangerous for. Hot for Teacher is a song by Van Halen.

18. As much as I wish I wasn't, I'm still learning. It's like you not inflating your grades, I can't not act out against people. But I'm trying.

inflate:to enlarge or amplify unduly or improperly.其实从inflation(通货膨胀)去理解，就很容易明白用在这里就表示故意给高分，夸大分数的意思。
act out: to express (unconscious impulses, for example) in an overt manner without conscious understanding or regard for social appropriateness

19. Lily: I'm not scared of you, Jack.
Jack: You should be.
Lily: You're high and you're not thinking clearly. You need to think about the repercussions of what you're doing.

high:这是一个很容易被误用的单词，虽然中文里我们常说“昨天玩的很high”，用high来表示cheerful, exciting之类的意思，但是在口语中，其实high是表示under the influence of alcohol or drugs，指的是因为喝酒、吸毒而使人很兴奋。
repercussions: 反响，后果

20. Chuck: I heard from the board that Jack is on his way back to Sydney. You didn't press charges.
Lily: No, I just wanted him gone.

press charges (against): 提出指控，撤销指控就是drop the charge
I just wanted him gone: 我只是想要他消失，注意gone做形容词这样的用法

21. Dan: How's the city working out for ya?
Carr: I think I'm getting the hang of it. Like anything else, you just have to make it work for you.

How's the city working out for ya: 还住的惯吗，还适应吗
I'm getting the hang of it: 熟能生巧，to succeed in learning how to do something after practicing it. e.g. After three weeks of using this computer I think I've finally got the hang of it.