The scenery of the Way-lee-way had charmed the travelers with its mingled ______ and grandeur and filled them with admiration and astonishment.

A．The Atmosphere and Our Environment
B．Research on Radiation
C．Effects of Space Radiation
D．Importance of Protection Against Radiation

A．exposure to even tiny amounts of radiation is fatal
B．the effect of exposure to radiation is slow in coming
C．radiation is avoidable in space exploration
D．astronauts in space suits needn't worry about radiation damage