同学们，实践是检验真理问题的唯一标准，运用你们学到的知识实践检验一下能力提升了吗?

Please give an example to explain the teacher’s roles in task-based teaching of speaking.

In task-based teaching of speaking, one task can be asking directions. Before the task, the teacher could be information provider and provide related words and expressions for students. S/he can even give an example of the task. During the task, the teacher can be a guider and helper if students have difficulty carrying out the tasks. S/he can also be a participant of the task. After the task, the teacher could be an evaluator to assess students’ completion of the task and come up with suggestions for the future.