Ⅲ.综合运用

Different Time Zones

Earth makes one full turn on its axis（轴）every 24 hours.As your location on earth rotates（旋转）into sunlight，you see the sun rise.When your location rotates out of sunlight，you see the s__1__.

Different parts of Earth enter and exit daylight at different times.So we need d__2__time zones.In order to build the time zone map，in the late 1800s，a group of scientists studied Earth's movements.They found that Earth m__3__about 15 degrees every 60 minutes and completes a full rotation of 360 degrees every 24 hours.The scientists used this information and d__4__the planet into 24 time zones.Each time zone is 15 degrees of longitude（经度）wide.The dividing lines begin at Greenwich，London.The time at Greenwich is called Greenwich Mean Time（格林尼治平时，GMT）.As you move west from Greenwich，every 15-degree time zone is an hour e__5__than GMT，while every time zone to the east is an hour l__6__.

Having different time zones makes people's life more convenient.No matter where you live,your noon is the middle of the day,while your m__7__is the middle of the night.

1.s____________2.d____________3.m____________4.d____________5.e____________6.l____________7.m____________