The task of preparing readers and writers is not of exclusive responsibility of first language teachers. Aware of this commitment, and being teachers and researchers in science education we feel challenged to expand the resources used by teachers in reading activities in the classroom. This article presents an analysis of one of these activities used in a pre-service teachers´ course in Brazil. Here, we explain our conceptions of language, reading, science and science education. Upon them we evaluate and characterize the activity of teaching that led to this research. Our data emerged from the analysis of students´ written production. This analysis allowed us to answer the following questions: (i) what are the characteristics of the questions raised by these subjects to mediate the reading of science textbooks? (ii) what demands these questions present to those who will answer them? (iii) what these questions reveal about the conception of the subjects of our research about the roles of teachers and students in the activity of reading science texts? The texts produced by the students revealed a limited conception of reading activities. This result reinforces the need of to treat with special attention the problem of mediation in reading activities during pre-service teacher’s courses and continuing education of teachers.