Analyze and comment on the word dull in the following sentences based on the characteristics of antonyms. [A] She became dull and silent during the last part of the journey. [B] I’m hearing a constant dull noise （whirring） that gets louder as I accelerate. [C] I got a right way to keep your face radiant and glowing even in this dull weather. [D] These factors affect both intelligent and dull children.