VOA慢速英语:专家了解夏威夷驼背鲸数量减少的原因

migrate - v. to move from one area to another at different times of the year

El Nino - n. a flow of unusually warm water along the western coast of South America that causes many changes in weather in other places (such as a lot of rain in areas that are usually dry)

blob - n. something that does not have a regular shape

determine - v. to learn or find out (something) by getting information

switch - v. make a change from one thing to another

reflect - v. to show (something): to make (something) known