可用来制铅笔芯的是 [ ]
A．铅
B．金刚石
C．石灰石
D．石墨
答案：D
林文前年买了8000元的国家建设债券，定期3年，到期后他取回本金和利息一共10284.8元．这种建设债券的年利率是多少？
Mr. Su _____ in Zhuyuan Middle School since 1998. He regards it his second home.
A．lives
B．lived
C．has lived
D．will live
