A．One is safe if he is very careful. B．Hi-tech safety equipment ensures one's safety. C．A lot of people do rock-climbing and they are OK. D．There are no dangerous places nearby to do rock-climbing.
A.One B. B．Hi-tech C. C．A D. D．There E.
【参考答案】
B 解析：选项中的safety equipment，no dangerous places，rock-clim......