问题
单项选择题
The pilot of a small aircraft with a 40-gallon fuel tank wants to fly to Cleveland, which is 480 miles away. The pilot recognizes that the current engine, which can fly only 8 miles per gallon, will not get him there. By how many miles per gallon must the aircraft’s fuel efficiency be improved to make the flight to Cleveland possible ？（）
A. 2
B. 4
C. 12
D. 40
E. 160
答案
参考答案：B
解析：
For an aircraft with a 40-gallon tank to fly 480 miles, it must average at least 480/40=12 miles per gallon. 12-8=4.