短语讲解：

1. Imagine never having to worry about traffic, stoplights, or road construction.

worry about 担忧， 烦恼; 惦念
例句：Don't worry about me; I'm very well.
别为我担心，我很好。

2. Kitty Hawk wants people to be able to buy its flying car by the end of 2017.

by the end of 到…为止
例句：By the end of the holiday I had spent all my money
到假期结束时，我已经花光了自己所有的钱。

3. The company has not yet said how costly air taxi travel would be compared to road taxi travel.

be compared to 与…相比；把…比作
例句：Our work can be compared to a battle.
我们的工作好比一场战斗。