如果x2+mx+9是一个完全平方式，则m的值为[ ]
A. 3
B. 6
C. ±3
D. ±6
答案：D
国库收支统计报表数据的来源？
It was strange that he _____ have uttered such rude remarks on that occasion.
A．must
B．could
C．should
D．would
