The Montreal protocol banning the use of CFCs was put into force in 1989. Explain why ozone layer has not yet fully repaired itself.

Which of the following is not a major characteristic used to identify minerals? a. hardness c. density b. magnetism d. luster select the best answer from the choices provided a b c d i know it is not d

Which pedigree symbol is used to represent a female carrier of a recessive x-linked trait? поө0 || save and exit submit

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.