—Your T-shirt is nice. It must be expensive.
—Not at all. I only spend $10 it.
A:in
B:on
C:for
D:of
站在北极点上所有方向指向 ( )
已知实数a,b满足a2﹣b2=10,则(a+b)3•(a﹣b)3的值是____
文段中表现狼“黠”的本性的句子有____,____,表现屠户警觉的句子是____。