【经典必背】
It's impossible to defeat a person who never gives up. 要战胜一个永不言弃的人是不可能的。
【课文原句】
It's easy to have a healthy lifestyle, and it's important to eat a balanced diet. 拥有一个健康的生活方式是容易的，饮食平衡也是很重要的。
It's necessary for us to have healthy eating habits. 我们拥有健康的饮食习惯是有必要的。
It's nice to have open space and pretty gardens. 拥有一个露天的空间和花园太好了。
【基础知识】
1. 此句型表示“对于（某人）来说做某事……”，句中的it是形式主语，后面的不定式是真正的主语。
It's good for the children to exercise every day. 孩子们每天锻炼是有好处的。
It's every important to sleep eight hours every day. 每天八个小时的睡眠是很重要的。
2. 在此句型中，有时It's后可直接接动词不定式构成的短语。
It's my first time to take part in the high jump. 这是我第一次参加跳高比赛。
It's his second time to visit Beijing. 这是他第二次游览北京。
3. 由此句型构成的还有It's time (for sb.) to do sth.和It's time for sth.，这两个句型可以互换，意为“到了做……的时间”。
It's time to have lunch. 到了午餐时间。
It's time for us to go to school. 到了上学的时间。
＝It's time for school.
4. 此句型中的it仅仅是一个形式主语，没有实际意义，真正的主语是后面的动词不定式。是为了避免头重脚轻而把动词不定式放在后面。
It's necessary for us to have healthy eating habits.
＝To have healthy eating habits is necessary for us.
It's nice to have open space and pretty gardens.
＝To have open space and pretty gardens is nice.
5. It's＋adj. ＋（for sb.）＋to do sth.有时可以和doing sth.作主语的句型作转换。
It's important for us to learn English well. 学好英语对我们来说很重要。
＝Learning English well is important for us.
It's interesting to collect stamps. 集邮很有趣。
＝Collecting stamps is interesting.