Time Zones（时区） Strange things happen to time when you travel

Time Zones（时区）
Strange things happen to time when you travel. Because the earth is divided into twenty-four zones one hour apart（相差）.You can have days with more or fewer than twenty-four hours, and weeks more or fewer than seven days.
If you make a five-day trip across the Atlantic Ocean(大西洋)，your ship enters a different time zone every day. As you enter each zone, the time changes one hour. Travelling west ,you set your clock back; traveling east , you set it ahead. Each day of your trip has either twenty-five or twenty-three hours.
If you travel by ship across the Pacific（太平洋）, you cross the international date line. By agreement, this is the point where a new day begins, when you cross the line, you change your calendar one full time day, backward or forward. Travelling east, today becomes yesterday; traveling west, it is tomorrow.
小题1:Strange things happen to time when you travel because______.

A．no day really has 24 hours	B．the earth is divided into time zones
C．time zones are not all the same size	D．no one knows where time zones are

小题2:From this passage it seems true that the Atlantic Ocean___.

A．is divided into five time zones	B．is divided into 24 time zones
C．is in one time zone	D．cannot be crossed in five days

小题3:If you cross the ocean going west, you set your clock_____.

A．ahead by 25 hours in a new time zone	B．one hour ahead for the whole trip
C．back one full day for each time zone	D．one hour back in each new time zone

小题4:The international date line is the name for______.

A．the beginning of any new time zone	B．the point where a new day ends
C．the point where a new day begins	D．any time zone in the Pacific Ocean