函数f(x)=x2+mx+1的图象关于直线x=1对称的充要条件是[ ]
A.m=-2
B.m=2
C.m=-1
D.m=1
答案:A
The technology of electronic products is ________changing, so you needn’t follow the fashion.
A.rarely
B.approximately
C.automatically
D.constantly
( )采用数量金额式明细账。
A.本年利润明细账
B.短期借款明细账
C.其他应收款明细账
D.原材料明细账