American schools ale looking for ways to save money on bus transport because of high fuel（燃料）prices．More children may have to walk，ride their bikes or find other ways to get to school．Soon，as another effect of the high prices，they may not have to go to school as often as before．Some schools are changing to a four-day week．That means longer days instead of the traditional Monday to Friday timetable．Beginning ill autumn，students in the Maccray school district（区域）in Minnesota will be in school from Tuesday to Friday Each school day will be sixty-five minutes longer．

In Custer，South Dakota，students have been going to school from Monday to Thursday since 1995．Superintendent（教育主管）Tim Creal said the change has saved about one million just over the past eight years．He has noticed other advantages，too．Students have more time to study．And activities that used to interfere with（干扰）classes are now held on non．school days．He said that in the future，an increase in online classes could make it possible to require even fewer days in school．High fuel prices are driving college students to take more online classes．In some states，high school students can take them，too．

1．Why do most American students have to go to school by bike or on foot?

2．How many days will students in Minnesota go to school every week from this autumn on?

3．What may American students do to save money in the future?

4．Is the change in Custer good or not? Why?

5．What is the main idea of the passage?