读图“埃博拉疫情爆发高风险区图”和“非洲气候类型的分布示意图”,非洲气候类型的分布规律是( )
A:南北延伸,东西更替
B:以赤道为中心,南北对称分布
C:从大陆中心向沿海更替
D:以0°经线为中心,东西对称分布
如图所示,小明在实验室里测量一块形状不规则、体积较大的矿石的密度.
计算:3a3•a2﹣2a7÷a2=____ .
Emmanuel Macron (born on 21 December 1977),
is a French politician(政治家).He was elected(选举)to be the new president of France on May 7,2017.
And his wife used to be his teacher, and she is 64 years old now.