在操作序列push(1)，push(2)，pop，push(5)，push(7)，pop，push(6)之后，栈顶元素是 (29) ，栈底元素是 (30) 。

A．7
B．6
C．5
D．1

—How do you like studying in the new school?

—Not so good.________, I miss my former classmates.[ ]

A. To be honest  

B. On the contrary

C. What's worse  

D. In general