The radiation amount of a mobile phone f
问题:
The radiation amount of a mobile phone for two half-hour periods per day is equal to ______ to an X-ray for ten seconds.
A.expose
B.exposing
C.exposed
D.being exposed
The radiation amount of a mobile phone for two half-hour periods per day is equal to ______ to an X-ray for ten seconds.
A.expose
B.exposing
C.exposed
D.being exposed