听力

例子: Angler fish lay eggs in deep sea, and the eggs will float to the surface of the sea where the younger Angler fish can enjoy enough food and sunlight. But when they grow older they predator will be a great threat to them. So they will migrate to the deep sea.

7.阅读

Title ： Predator Release

定义： When human control the number of predators, the population of preys will increase. This will lead to some consequences.

听力

例子: Sea urchins feed on coral reefs. Trigger fish feed on sea urchins. But recently, tourists came fishing, causing the decline of

trigger fish. As a result. sea urchins grow to larger size, destroying coral reefs, which are habitats for many ocean animals.

8.阅读

Title：Fear Appeal

定义： When companies make advertisement to attract consumers, one of the strategies they adopt is called fear appeal. That is, they present some negative events or outcome people may encounter, and then provide solutions with their products or service.