The best way is a combination of several things: physical interaction with others of its own kind or specially-trained human companions, desirable features in the enclosure such as swimming pools and ledges for perching and sleeping, and toys to play with. The use of a colon in this sentence is correct because A) colons can be used in place of a period. B) colons and semi-colons are interchangeable. C) colons separate two independent clauses into sections in the sentence. D) colons should be used after independent clauses that come before lists.

How do high-energy electrons from glycolysis and the krebs cycle contribute to the formation of atp from adp in the electron transport chain? a. high-energy electrons interact with pyruvic acid to create a phosphate bond with adp, forming atp. b. high-energy electrons supply the needed energy to synthesize atp from the lower-energy adp in the electron transport chain. c. high-energy electrons supply a negative charge which causes the citric acid to oxidize, forming a phosphate group to bond with adp. d. high-energy electrons increase the temperature of adp so it easily reacts to form atp.