用“what, why, which, when, how'填空,完成下面的疑问句。(注意首字母要大写) 1. ____________ is Li Ming doing? He is reading a book. 2. ____________ did you go to Shanghai? By plane. 3. ____________ do you like winter? Because I can ski. 4. ____________ season do you like best? Fall. 5. ____________ did you come to Canada? At 7: 00.