【正文】
t B. mustn’t C. shouldn’t D. may not ( ) 4. —Could you please go to the cinema with me this afternoon? —Sorry, I ______. I _____ take a piano lesson at 2 pm. A. couldn’t。 1. Drinking and smoking can (損害 ) a person’s health. 2. You should make your dream e true through your own (努力 ). 3. “We have already tried four times. Should we try a (第五 ) time?”