There is a tree which is 1500 years old.= There is a ________ tree.

问题描述:

There is a tree which is 1500 years old.= There is a ________ tree.

There is a 1500-year-old tree.
1500-year-old 连接起来变成一个形容词,意为“1500岁的”.
注意连起来的时候year不加s.