Point to the blackboard 这个短语源自于英语的教学语境，在课堂上指示学生注意黑板上的内容。
例句：
Could you please point to the blackboard?
请你指向黑板好吗？
The teacher pointed to the blackboard and asked the students to pay attention.
老师指着黑板，要求学生注意。
The student pointed to the blackboard and started to explain the formula.
学生指着黑板，开始解释公式。