A. How to care for precious metals.
B. A standard unit for measuring weight.
C. The value of precious metals.
D. Use of the metric system.
A. To check the accuracy of scales.
B. To calculate the density of other metals.
C. To observe changes in the atmosphere.
D. To measure amounts of rainfall.
A. Someone spilled water on it.
B. It was not very endurable.
C. It was made of low quality metal.
D. The standard for measuring had changed.
A. It is a small amount to pay for so much precious metal.
B. It is difficult to judge the value of the object.
C. It is too high for such a light weight.
D. It is reasonable for an object with such an important function.