A:动脉管壁厚,血流速度快
B:静脉有的分布较浅,如手臂上的“青筋”
C:血液在血管中流动方向是:动脉→静脉→毛细血管
D:毛细血管中,红细胞呈单行通过
如图,象棋盘上,若“将”位于点(1,﹣1),“车”位于点(﹣3,﹣1),则“马”位于点 ____ .
某彩金是在黄金中加入铜、银等熔炼而成的合金,常用于制造首饰.从物质分类的角度看,彩金属于( )
Mike is a boy. He is seven years old. His birthday is September 9. He is 1.4 metres tall. He lives in a house near the park. His address is 36 Park Road. He likes to read books on Sundays.
对青春的正确理解是( )