单项选择题
"You are not a new member, are you""（）. I joined only yesterday."
A．No, I'm not B．Yes, I'm not C．No, I am D．Yes, I am
单项选择题 The school is more beautiful now than（）in the past.
单项选择题 We should（）study hard during our time in the university.
单项选择题 The book is a（）for students of science.
