1) 经常性或习惯性的动作，常与表示频腮度的时间状语连用。时间状语： every…, sometimes, at…, on SundayI leave home for school at 7 every morning.2) 客观真理，客观存在，科学事实。The earth moves around the sun.Shanghai lies in the east of China.3) 表示
