A:﹣a2+b2
B:﹣x2﹣y2
C:49x2y2﹣z2
D:16m4﹣25n2
公元前217年,某商人在宛(今河南南阳)交易时使用蚁鼻钱(楚国货币),被当地官府依据《金布律》处罚。这表明( )
同种生物从古代到现代的进化,最有力的证据是( )
Not having __________ her daughter abroad for a long time, the mother was very worried.