单项选择题
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 spacesuits needn’t worry about radiation damage
A．that B．when C．what D．which
A．A solid foundation in basic mathematics and Asian culture B．Hard work and intelligence C．Hard help and a limited knowledge of English D．Asian culture and the American educational system