is-a-role-of.rb

class Person
	attr_accessor :name, :gender, :height, :weight
	def initialize(name, gender, height, weight)
		@name = name
		@gender = gender
		@height = height
		@weight = weight
	end
	def cry
		"woooo"
	end
end


class Student < Person
	attr_accessor :student_id
	def initialize(name, gender, height, weight, student_id)
		super(name, gender, height, weight)
		@student_id = student_id
	end
	def study
		"Student #{name} with #{student_id} is studying now"
	end
end

s = Student.new("Lin", "Male", 173, 75, 666777)
puts s.cry()
puts s.study