or的用法歸納：

　　1、表示選擇，意為“或”“還是”：

　　Is the radio off or>Would you prefer tea or coffee? 你喜歡茶還是咖啡?

　　Is he asleep or awake? 他睡著了還是醒著?

　　Are you going to America by boat or by air? 你到美國是坐船還是坐飛機(jī)?

　　You may go or stay, according as you decide. 是去是留由你自己決定。

　　Are you from North China or South China? 你是華北人還是華南人?

　　You can come now or you can meet us there later. 你可以現(xiàn)在來，也可以稍晚和我們在那里碰頭。

　　2、表示一種否定的條件，意為“否則”：

　　Come on, or we’ll be late. 快點(diǎn)，否則我們要遲到了。

　　Hurry up, or you'll be late for school.趕快，否則你上學(xué)就要遲到了。

　　Dress warmly, or else you’ll catch cold. 穿暖和點(diǎn)，否則你會感冒的。

　　Be careful, or you’ll break that vase! 小心，否則你會把那花瓶打碎!

　　Cross the road very carefully. Look both ways, or you might be knocked down. 過馬路要非常小心，要看兩邊，不然會被車撞倒。