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1·This type of equal arm balance with double beam and pan adopts flexible steel band as support without abrasion to the edges of the knife.

复梁式双盘等臂天平，采用钢带弹性作支撑，无刀口磨损现象发生。

2·You have 3 weights:1 kg, 3 kg and 9 kg as well as an equal arm balance, as shown. How many different weight objects can you weigh with these three?

翻译：你有3个砝码：1公斤、3公斤和9公斤，以及一个托盘天平，你可以称出多少个不同的重量？