Answer:
The teacher instructed the students, "Take your exercise books out now." To change the mode of narration, you can rewrite the sentence in indirect speech.
In indirect speech, we report what someone said without using their exact words. To do this, we usually need to make changes to the tense, pronouns, and word order.
Here's how you can change the sentence into indirect speech:
The teacher instructed the students to take their exercise books out then.
In this example, we have changed the direct speech ("Take your exercise books out now") into indirect speech ("The teacher instructed the students to take their exercise books out then"). We removed the quotation marks and used the verb "instructed" to report the teacher's instruction. We also changed the tense of the verb "take" from present tense to past tense ("take" to "took"). Additionally, we changed the word "now" to "then" to match the reporting of past events.
Remember, when changing direct speech to indirect speech, you need to consider the verb tense, pronouns, and other necessary changes to make the sentence grammatically correct.