Which halogen is a fatal poisonous gas, but is put in drinking water and swimming pools to prevent serious diseases?

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.

Which number represents a basic ph, 4 or 9? numerical answers expected! answer for blank 1: i'll give

Which organ controls breathing? lungs alveoli heart diaphragm