Indicate appropriate brick and mortar selections for each of the following situations by mentioning the minimum brick strength grade, its appearance type and the necessary mortar type. a. Little Rock, Arkansas: Exterior load bearing walls for a 17-story dormitory with a highly-regular and smooth appearance.
b. Palm Springs, California: Brick retaining wall with a very rough texture.
c. Winnipeg, Manitoba, Canada: Veneer wall inside a shopping mall, with a "hand-made brick" look.

In a unit cell of fcc structure, indicate the position of one of the tetrahedral interstitial sites by plotting the corresponding tetrahedron. do the same for one of the octahedral interstitial sites (in a separate fcc unit cell). mark the positions of all the tetrahedral and octahedral interstitial sites in the unit cells. how many equivalent tetrahedral sites and how many equivalent octahedral sites are contained in a fcc unit cell, respectively. what is the coordination number for a tetrahedral site and what is the coordination number for an octahedral site?