Question 1

The focus of Dava Sobel’s 2016 book The Glass Universe is a group of women at the Harvard Observatory who transformed the field of astronomy. Fill in the blank with the word that Sobel pairs with "supplement "in the sentence below.

Within the Bruce telescope’s first few months of operation in Peru, it produced photographic charts of the entire southern sky. These images at once supplemented and _________ the existing southern star catalogues.

Fill in the blank.