VOA慢速英语:词汇节目:难以理解

source – n. someone or something that provides what is wanted or needed

perplexing – adj. difficult to understand : causing confusion

confusing – adj. to make (something) difficult to understand

tough – adj. difficult to accomplish, resolve, endure, or deal with

riddle – n. a puzzling question to be solved or answered by guessing

enigma – n. something hard to understand or explain

intention – n. the thing that you plan to do or achieve : an aim or purpose

forecast – v. to say that (something) will happen in the future : to predict (something, such as weather) after looking at the information that is available

key – n. something extremely important