51. Dactylology is the study of ____:

52. Demography deals with ____:

53. Dendrochronology is the study of ____:

54. Dendrology is the study of ______:

55. Dermatology is the study of ___:

56. Ecology is the study of ___:

57. Economics deals with ___:

58. What does Electrostatics study?

59. Embryology is the study of ____:

60. Endemiology is the study of _____: