The teacher decided to pretest the exam with a small class to make sure the questions were suitable for all students.

pretest 是由前缀 pre-（表示“在...之前”）和名词 test（测试）组成的复合动词，意思是“预先测试”或“预考”。在这里指在正式考试前先进行小规模测试，以评估试卷的难度和适用性。