We have worked for three hours. Now let’s stop a rest.
A:had
B:have
C:to have
D:having
隋朝大运河的一段利用了春秋时期吴王夫差开凿的古运河.这一段是( )
读图,图中②处等高线的弯曲部分向低处凸出,该地形部位的名称是( )