1. It is a positive, silent sign sent with the hope the other person will smile back.
    这是一种积极的、无声的信号，发出这个信号的人希望别人也以微笑回报。

2. I tell him to hold tight, and back and forth he goes.
    我告诉他手要握紧，然后他一前一后地荡起来。

3. I climbed into the back-seat of the world's hottest jet fighter, the F-16.
    我登上世界上最新式的喷气式战斗机F-16的后座，

4. In Thailand, back-seat passengers are advised not to rest their feet on the seat in front of them, which drivers consider rude as feet are considered the lowest, dirtiest part of the body.
    在泰国，坐在后座的乘客被劝告不要把脚搁在自己身前的座位上，因为司机觉得这很粗鲁（脚被认为是身体上最低等、最肮脏的部分）。

5. It wasn't as if I had a lot to go back to in the States.
    好像并没有很多事情等着我回美国去做，

6. From one´s own front door to home or foreign hills or sands and back again, everything is to hand.
    从自己的家门出发到国内国外的山区或沙滩上露营然后返回，一切都很便利。

7. For a few hours, you settle back in a deep armchair to enjoy the flight.
    几小时之内，你躺在扶手椅上，享受着旅途的欢乐。

8. For university students, like those in Harvard, Cambridge, or Massachusetts: cheaters are normally required to leave for two back-to-back terms.
    大学生作弊：如哈佛大学、剑桥大学或麻省理工学院的学生，一旦被发现作弊，通常必须连续休学两个学期。

9. Finally, if I was lucky, they called back and approved the repair.
    最后，如果我幸运的话，他们会给我回电话，同意维修。