There are two weights of 1 gram, 2 grams, and 4 grams each, and 2 weights are taken out of them. How many objects of different masses can be weighed in total?
有1克、2克、4克的砝码各两个，从中取出2个砝码．一共可以称出多少种不同质量的物体．
<gadget id="calculator">3 + 3 + 1</gadget>
<output>7</output>

<result>7</result>