[单项选择]Hurricanes are violent storms that cause millions of dollars in property damage and take many lives. They can be extremely dangerous, and too often people underestimate their fury.
Hurricanes normally originate as a small area of thunderstorms over the Atlantic Ocean west of the Cape Verde Islands during August or September. For several days the area of the storm increases and the air pressure falls slowly. A center of low pressure forms, and winds begin to whirl around it. It is blown westward, increasing in size and strength.
Hurricane hunters then fly out to the storm in order to determine its size and intensity and to track its direction. They drop instruments for recording temperature, air pressure, and humidity (湿度), into the storm. They also look at the size of waves on the ocean, the clouds, and the eye of the storm. The eye is a region of relative calm and clear skies in the center of the hurricane. People often lose their lives by leaving shelter when the eye has ar
A. the powerful center of the storm
B. the part that determines its direction
C. the relatively calm center of the storm
D. the center of low pressure

[单项选择]Hurricanes are violent storms that cause millions of dollars in property damage and take many lives. They can be extremely dangerous, and too often people underestimate their fury.
Hurricanes normally originate as a small area of thunderstorms over the Atlantic Ocean west of the Cape Verde Islands during August or September. For several days the area of the storm increases and the air pressure falls slowly. A center of low pressure forms, and winds begin to whirl around it. It is blown westward, increasing in size and strength.
Hurricane hunters then fly out to the storm in order to determine its size and intensity and to track its direction. They drop instruments for recording temperature, air pressure, and humidity (湿度), into the storm. They also look at the size of waves on the ocean, the clouds, and the eye of the storm. The eye is a region of relative calm and clear skies in the center of the hurricane. People often lose their lives by leaving shelter when the eye has ar
A. A storm surge is a dramatic increase in wind velocity.
B. A hurricane watch is more serious than a hurricane warning.
C. Falling air pressure is an indicator that the storm is increasing in intensity.
D. It is safe to go outside once the eye has arrive

[单项选择]