由雪变成冰川冰有（）、（和（）三种方式；三种成冰作用方式中以（）最快。
参考答案：重结晶作用，升华-凝华作用，压实作用，重结晶作用
名句春花秋月何时了往事知多少出自哪里？
How can we meet the needs of today without diminishing the capacity of future generations to meet theirsSustainable development implies a broad view of human welfare, a long-term perspective about social development.
Write an essay which should cover：
1) describing the set of drawings below；
2) stating its main idea and
3) giving your comment.
