Final answer:
The strategy of leading a class discussion and creating a semantic map on the chalkboard is helpful to ESL students mainly because it a. allows them to develop or review key concepts and vocabulary.
Step-by-step explanation:
This strategy is helpful to ESL students primarily because it a. allows them to develop or review key concepts and vocabulary. By leading a class discussion and creating a semantic map on the chalkboard, the science and ESL teachers provide visual and interactive support for the students to understand the topic of earthquakes.
This collaborative approach helps ESL learners to engage with the material, clarify their understanding, and reinforce their knowledge of the subject.