Why do cementite plates appear as dark lines in the fine pearlitic microstructure when viewed under a general optical microscope?

Which of the following is an easy way to remember the modified “x” tire rotation? a. nondrive wheels straight, cross the drive wheels b. drive wheels straight, cross the nondrive wheels c. drive wheels crossed, nondrive wheels straight d. drive wheels crossed, nondrive wheels crossed

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false