--- Who helped you clean the classroom yesterday? --- _______. I cleaned it all by myself.

---What major will you choose when you are at university?---____ but English, which has brought terrible dreams to me for the past 12 years. 

 He is the most hard-working students in his class. That means he is more hard-working than_______ in his class.

---Susan, go and join your sister cleaning the yard. --- Why ___? John is sitting there doing nothing. 

          worries me the way he keeps changing his mind.