13. chemical bonds a. combine compounds to form elements. b. are always covalent. c. hold atoms together to form compounds. d. are always ionic.

answer; ///i do believe that the correct answer is (c) hold atoms together to form compound;

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.

answer: 45

explanationyou have to add as well to be it could be