阅读填空，根据短文内容及所给单词的适当形式填空。

Another example is a 2011 proposal for a tall "Birdscraper" building in New York. The building is intended 【小题1】(protect) birds and fight pollution at the same time. It would be in the middle of a lake, birds would sit on it, and their droppings would fall into the water. The droppings would feed water plants【小题2】would then create oxygen through photosynthesis(光合作用).

If we learn to share our space, we can become better neighbours to the wildlife around us. If we do not, more species will become extinct and our own future will 【小题3】(endanger).