水果和蔬菜的主要化学组成有：水、碳水化合物、（）、有机酸、维生素、矿物质等。
参考答案：色素
We all feel it is Jack as well as his wife that for their son's bad performance at school.
A．are to blame
B．is to the blamed
C．are to be blamed
D．is to blame
各设备的保护地线严禁复接，若存在复接，都应将其拆除，新设保护地线，保护地线宜采用25mm2的铜导线。（）
