the beam is constructed from two boards fastened together at the top and bottom with three rows of nails spaced every 4 in.

Carbon monoxide is usually more dangerous indoors.

Ghana, first of the great medieval trading empires of western africa (fl. 7th–13th century). it was situated between the sahara and the headwaters of the sénégal and niger rivers, in an area that now comprises southeastern mauritania and part of mali.

The correct answer is b