C 
Yellowstone Weather 
　　Yellowstone National Park is at high altitude(海拔).Most of the park is above 7,500 feet (2,275 meters). 
　　Yellowstone’s weather is unpredictable. In summer, it may be warm and sunny with temperatures in the high 70s. At night in any given month, the temperature may drop close to freezing. So it is best to come prepared for cold evenings and mornings, especially if you are camping or hiking. When you leave your campsite, please leave it prepared for possible thundershowers and wind. 
　　A sunny warm day may become fiercely stormy with wind, rain, sleet and sometimes snow. Without enough clothing, an easy day hike or boat trip can turn into a battle for survival. 
　

Seasonal Weather Information 

Seasonal Weather Information
Spring Cold and snow continue into May, although temperatures gradually climb. Early in spring, daytime temperatures average in the 40s to 50s; by late May and June, they may reach the 60s and 70s. Nighttime lows fall below freezing.	Summer Daytime temperatures are usually in the 70s, occasionally reaching the 80s in the lower elevations(高度).Nights are cool, temperatures may drop in the 40s and 30s —sometimes even the 20s. June can be cool and rainy; July and August tend to be somewhat drier, although afternoon thundershowers are common.
Fall Weather can be pleasant, although temperatures average 10-20 degrees lower than summer readings. Nighttime lows can fall into the teens and lower. Snowstorms increase in frequency as the weeks go by or towards the end of the fall season.	Winter Temperatures often stay near zero throughout the day, occasionally reaching high in the 20s. Subzero nighttime lows are common. Annual snowfall averages nearly 150 inches in most of the park. At higher places, 200-400 inches of snow have been recorded.

Spring 
Cold and snow continue into May, although 
temperatures gradually climb. Early in spring, daytime temperatures average in the 40s to 50s; by late May and June, they may reach the 60s and 70s. Nighttime lows fall below freezing. 

Summer 
Daytime temperatures are usually in the 70s, occasionally reaching the 80s in the lower elevations(高度).Nights are cool, temperatures may drop in the 40s and 30s —sometimes even the 20s. June can be cool and rainy; July and August tend to be somewhat drier, although afternoon thundershowers are common. 

Fall 
Weather can be pleasant, although temperatures average 10-20 degrees lower than summer readings. Nighttime lows can fall into the teens and lower. Snowstorms increase in frequency as the weeks go by or towards the end of the fall season.

Winter 
Temperatures often stay near zero throughout the day, occasionally reaching high in the 20s. Subzero nighttime lows are common. Annual snowfall averages nearly 150 inches in most of the park. At higher places, 200-400 inches of snow have been recorded. 

64. The author writes this passage most probably for those who plan to ________ in Yellowstone National Park. 
A. do research work                    
B. take a business trip  
C. have sports games                   
D. Spend their holidays or take a tour 

65. Which of the following best describes Yellowstone’s weather? 
A. Yellowstone’s weather is generally changeable and it snows most of the year. 
B. It’s neither too hot in summer nor too cold in winter. 
C. Weather in fall is pleasant and temperatures never fall below freezing. 
D. It’s pretty warm in the day and very cold at night throughout the year. 

66. If you are planning to spend your holiday in Yellowstone National Park in summer, what should you take with you? 
A. Just some light clothing such as T-shirts or skirts. 
B. Just some warm clothing such as sweaters and coats. 
C. Both light clothing and warm clothing. 
D. Either light clothing or warm clothing. 

67. What does the underlined word “readings” refer to? 
A. literature works      B. books     C. announcements      D. figures