Add my answer to Exercise 3.67.

Included are the following 2 files:

	Exercise_3.67.scm
	Test_for_Exercise_3.67.scm

Thank you!
							Lawrence X. Amlord
							  Dec 3rd, 2013
							  Xi'an, China
Add my answer to Exercise 3.68.

Included are the following 3 files:

	Exercise_3.68.pdf
	Exercise_3.68.scm
	Exercise_3.68.tm

Thank you!
							Lawrence X. Amlord
							  Dec 4th, 2013
							  Xi'an, China