A.They haven’’t devoted as much energy to medicine as to space travel.B.There are too many kinds of cold viruses for them to identify.C.It is not economical to find a cure for each type of cold.D.They believe people can recover without treatment.
A.They haven’’t devoted as much energy to medicine as to space travel.
B.There are too many kinds of cold viruses for them to identify.
C.It is not economical to find a cure for each type of cold.
D.They believe people can recover without treatment.