travel表示“旅行”的时候，不可数；表示“旅游”的时候，可数。
travel /ˈtrævəl/ CET4 TEM4 ( traveling, traveled, travels )
1. V-T/V-I If you travel, you go from one place to another, often to a place that is far away. 旅行
例：
You had better travel to
Nova Scotia tomorrow.
你最好明天去
新斯科舍。
例：
I've been travelling all day.
我一整天都在旅行。
例：
Students often travel hundreds of miles to get here.
学生们常常要旅行数百英里才能到这儿。
2. N-UNCOUNT Travel is the activity of travelling. 旅行
例：
Information on travel in New Zealand is available at the hotel.
新西兰的旅游信息在该酒店可以查到。
例：
He detested air travel.
他厌恶空中旅行。
3. V-T If you travel the world, the country, or the area, you go to many different places in the world or in a particular country or area. 游历
例：
He was a very wealthy man who had traveled the world.
他是个非常富有的人，曾经
周游过世界。
4. V-I When light or sound from one place reaches another, you say that it travels to the other place. (光或声音) 传播
例：
When sound travels through water, strange things can happen.
当声音在水中传播时，奇怪的事情会发生。
5. V-I When news becomes known by people in different places, you can say that ittravels to them. (消息) 流传
例：
News of his work traveled all the way to Asia.
有关他工作的消息一直传到了亚洲。
6. N-PLURAL Someone's travels are the trips that they make to places a long way from their home. 旅游
例：
He also collects things for the house on his travels abroad.
他在国外旅游时也为家人收集些东西。
7. PHRASE If you travel light, you travel without taking much luggage. 轻装旅行
例：
It would be good to be able to travel light, but I end up taking too many clothes.
能够轻装旅行再好不过，但我最终还是带了太多衣服。