四六级考试

【单选题】 Why do tornadoes appear to be dark
A．They occur only at night.
B．They are funnel - shaped.
C．They pick up debris from the ground.
D．They are water - laden.

网考网参考答案：C
网考网解析：
[试题分析] 本题是一道细节题。 [详细解答] 这道题的解题关键就是文中"As this funnel dips earthward, it becomes darker because of the debris that is forced into its intensifying vortex." 查看试题解析出处>>