单项选择题
A.A flood wall was built. B.Rescue teams were formed. C.An alarm system was set up. D.50 underground stations were made waterproof.
A.Whether global warming will speed up in the future. B.Whether it will lead to widespread food shortage. C.Whether it can be detected and checked. D.Whether it will affect their own lives.
A.The heart of London was flooded. B.An emergency exercise was conducted. C.100 people in the suburbs were drowned. D.One of the bridges between North and South London collapsed.