It makes you feel sad once we think of those animals which are endangered.追问：It's sad _________ ___________ ___________ pands and other animals in danger.回答：It's sad ( to think of ) pandas and other animals in danger.
It makes you feel sad once we think of those animals which are endangered.追问：It's sad _________ ___________ ___________ pands and other animals in danger.回答：It's sad ( to think of ) pandas and other animals in danger.