The best way to use reported speech in the sentence “This is a tragedy.” is:
The author of the text said
The best possessive adjective to complete this sentence “the use of chemicals and ______ impact on the environment are phenomenal” is 
The word marketing in “It also extends to the marketing of such organisms in a controlled environment” functions as 
The conjunction therefore in “and therefore it requires inputs” conveys an idea of 
The adverb often in “Inputs often depend on the species that are farmed” can be replaced by the adverb 
The word as in “as they feed on microorganisms” can be substituted by 
The best way to complete the sentence “Aquaculture will add to wild seafood, and make it _______ and accessible to all” is 
The best negative form of the sentence “Aquaculture business provides tax and royalty revenue to local governments” is 
Based on text CB1A5AAA, judge the following items.
The words “unaware” (l.12) and “wary” (l.16) are related in terms of meaning, being both connected to the notion of caution and attention.
Based on text CB1A5BBB, judge the following items.
In the fragment “on becoming director of the American National Security Agency” (l. 9 and 10), the preposition “on” refers to a period when the action is taking place.