单选题 According to the passage, some tornadoes take people unaware because they

A、 produce a sound similar to thunder.
B、 cannot be seen until it is too late.
C、 look so much like other clouds.
D、 carry so many large pieces of debris.

【正确答案】 B

【答案解析】[试题分析] 本题是一道简单分析题。 [详细解答] 这道题考生注意到文中“Some tornado give no visible warning until their distraction strikes the unsuspecting victim.”“no visible”也就是“cannot be seen.”