Not far from the school there was a garden,      owner seated in it playing chess with his little grandson every afternoon.

A．its

B．whose

C．which

D．that

下列各组材料中，都是导体的一组是（　　）

A．铜、陶瓷、大地

B．油、橡胶、石墨

C．铁、塑料、玻璃

D．铝、人体、盐水