test characteristic function

例句：

1. 1. The engineer tested the new machine before it was put into use.
   工程师在机器投入使用前对其进行了测试。
2. 2. The scientists conducted a thorough test of the new drug.
   科学家们对新药进行了彻底的测试。
3. 3. Before making any decisions, we must conduct a thorough test of our ideas.
   在做任何决定之前，我们必须对我们的思想进行彻底的测试。