18. When I am confronted with such questions, my mind goes __, and I can hardly remember myown date of birth.

• A、 faint

• B、blank

• C、dark

• D、blind

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42. Which ability is most important for dogs to rescue people trapped in snow?

• A、Sharp hearing.  

• B、Swift movement.

• C、Extraordinary smelling.

• D、A strong memory.