linear contraction tester of casting alloy

例句：

1. 1. The line of the road is straight as an arrow.
   这条路线直得像箭一样。
2. 2.The data is linearly proportional to the amount of light.
   数据与光量成正比例关系。
3. 3. The graph is linear, showing a direct relationship between the two variables.
   这个图表是线性的，显示了两个变量之间的直接关系。