$8.$ The recommended fall per foot for a $2^{\text{'}\text{'}}$ horizontal waste line is

C$.{32}_2.$

D$.\frac{5}{6^{\text{'}\text{'}}}=$

A$.{38}^{\text{'}\text{'}}.$

B$.x_1=$

$9.$ In a building that is to have a combined sanitary and storm sever in estimating the roof surfaces in terms of fixture units you would a fixture unit as being equivalent to

A$.12\mathrm{.}0sqft$ of horizontal surface.

C$.,5\mathrm{.}2sqft$ of horizontal surface.

B$.10\mathrm{.}5sqft$ of horizontal surface.

D$.3\mathrm{.}9sqft$ of horizontal surface.

$10.$ In Fig. I the

A$.4"$ stack vent should be increased at roof.

B$.$ grease trap is improperly connected.

C$.4^{\text{'}\text{'}}$ soil is too small.

D$.3^{\text{'}\text{'}}$ soil is too small.

$11.$ As a rule, the diameter of a leader should not exceed

A$.8^{\text{'}\text{'}}.$

B$.6^{\text{'}\text{'}}.$

C$.5^{\text{'}\text{'}}.$

D$.4^{\text{'}\text{'}}.$

$12.$ Where the soil is of satisfactory absorption the depth of trench for sub surface drain tile should be not more than