试探者

例句：

1. 1. The scientist conducted a series of experiments to determine the effectiveness of the new drug.
   科学家进行了一系列的实验，以确定新药的有效性。
2. 2. The engineer tested the machine before it was put into operation.
   工程师在机器投入使用前对其进行了测试。
3. 3.The teacher asked the students to be testers during the exam.
   老师要求学生们在考试期间担任试验员。