教师寄语：There is no royal road to science, and only those who do not dread the fatiguing climb of gaining its numinous summits. (在科学上没有平坦的大道，只有那些不畏劳苦攀登的人们，才有希望达到它神圣的顶点。)
学习目标：
1. 知识目标：babysit, plan, how long, away, get back, send, postcard.
What are you doing for vacation?
I’m going camping.
That sounds nice.
I’m going hiking on the mountains.
I don’t like going away for too long.
