下列哪种物质是人体内的备用能源物质 [ ]
A．糖类
B．蛋白质
C．脂肪
D．维生素
答案：C
The guests are looking forward every moment to _______ to China again.
A．honor; visit
B．honored; pay a visit
C．honored; paying a visit
D．honoring; visiting
600mm的管钳的合理使用范围为（）mm。
A、40～50
B、50～62
C、62～76
D、76～84
