Challenge

其實有好多字都可以解釋challenge
例如confront,dare,defy,dispute都可以
只要自己識得轉番做(adj),(v)就會有好多字用
希望你記住d字點解同點用la

"Formidable" is a very common adjective, but a "formidable challenge" may not be easily overcome.
I was greatly impressed by the word "formidable" when President Reagan pronounced the word with the accent on the second syllable. But as a Hong Kong student, I was accustomed to pronouncing the adjective with the accent on the first syllable. I have been wondering why the Americans choose to oppose the British in pronouncing some such common words.

challenging