(i) in great dread of: a feeling of great fear about something that might or will happen in future (for instance here—scolding by his teacher).
(ii) counted on : to trust somebody to do something or to be sure that something will happen.
(iii) thumbed at the edges : to touch something with your thumb or thumbs, for instance here the edges of the old primer.
(iv) in unison : to do or say something at the same time (here repeating the lesson at the same time).
(v) a great bustle : extremely busy and noisy activity, (for instance here tumult before opening of the school).
(vi) reproach ourselves with : to blame or criticise somebody for something that they have done or not done, because you are disappointed in them.
The Last Lesson Think as you read (Page 7)