The Class 10000 ISO7 (“I-S-O-seven”) standard for these facilities requires an ACH (“A-C-H”) of an inverse minute. While at Sandia National Lab, Willis Whitfield pioneered usage of laminar flow in these facilities. Clair Cameron Patterson effectively turned his lab into one of these facilities while (10[1])trying to date the Earth. In the “recirculating” class of these facilities, flow is drawn into the ceiling plenum (10[1])before being passed through a HEPA (“HEP-uh”) system. NASA’s (10[1])Goddard Spaceflight Center has the world’s largest one of these facilities (-5[1])where assembly of sensitive equipment occurs. (10[1])Semiconductor fabs contain these tightly controlled facilities where integrated circuit manufacture occurs. For 10 points, people must take an “air shower” before entering what spaces with very low airborne particulate concentrations? (-5[1])■END■ (10[1]0[1])