John’s house became too big for him after his wife died, so he bought a smaller one

nearby. There is a very nice old clock in his first house. When some people came to help

move a clock, John thought, “I won’t let them take off my beautiful old clock in the truck.

Perhaps they are likely breakit.” So she carried it on his arms. One the way, a small boy

looked at John for a few second and said, “How interested you are! Why did you buy so a

large watch?”

烟雾会使飞行员产生怎样的错觉？