•Laughing stock (idiom) - Someone or something that seems stupid or silly, especially by trying to be serious or important and not succeeding.

　　（笑柄，笑料）

　　Examples:

　　1.Another performance like that and this team will be the laughing stock of the league.　　

　　2.After the event and how he behaved there, he was the laughing stock in school for days to come.

　　•Undoing (noun) - If something is someone's undoing, it is the cause of their failure.（失败的原因）

　　Examples:

　　1.His lack of experience may prove to be his undoing.　　

　　2.Greed has been the undoing of many a businessman.

　　•Sling/throw mud at sb (idiom) - To say insulting or unfair things about someone, especially to try to damage their reputation.（污衊，泼髒水）

　　Examples:

　　1.This newspaper became famous for slinging mud at movie stars.　　

　　2.The candidates started slinging mud at each other early in the campaign.

　　•Be/get bogged down (idiom) - To be/become so involved in something difficult or complicated that you cannot do anything else. （陷入（困境、泥沼））

　　Examples:

　　1.Let's not get bogged down with individual complaints.　　

　　2.The car got bogged down in the mud.

　　•Cater to (phrasal verb) - To provide what is wanted or needed by someone or something.（满足…的愿望，提供…的需求）

　　Examples:

　　1.Internet shopping caters to every conceivable need.　　

　　2.There's a strong financial incentive for British universities to make sure they cater to the tastes of Chinese students.