'1 of the 2 units, each 3 letters long & starting with "R", that measure radiation exposure from X-rays'
rads (or REM)
TAKING SPECIAL MEASURES: 1 of the 2 units, each 3 letters long & starting with R, that measure radiation exposure from X-rays
1 of the 2 units, each 3 letters long & starting with "R", that measure radiation exposure from X-rays
1 of the 2 units, each 3 letters long & starting with "R", that measure radiation exposure from X-rays
TAKING SPECIAL MEASURES
rads or REM
TAKING SPECIAL MEASURES