迄今，中国国内发现最大的一颗钻石原石是（）。
A.金鸡钻石
B.常林钻石
C.陈埠一号钻石
D.元红钻石
参考答案：B
Don't ______. I'll help you.[ ]
A. worry
B. worried
C. be worry
D. to worry
David felt________of the foolish thing he had done in the classroom. [ ]
A. shameful
B. ashamed
C. shamed
D. shaming
