A green light bar at the top of my steering wheel showed that Super Cruise was on. There were no shake, no sudden speed changes or anything like that. The car remained perfectly steady. It uses a combination of cameras, radar sensors, and GPS to find the center of the lane. The car found it, like a train on a track.

　　I had to admit that I was little worried about letting the car take over at first. I kept my hands near the wheel and my eyes locked on the road. After about ten minutes, I finally started to trust the car's judgment. It soon became clear that it could easily drive itself in light traffic, braking when necessary and keeping a steady speed.

　　Then we hit a bottleneck. There was a standstill traffic outside of Baltimore, and things could have easily gone wrong, but this is where Super Cruise really shined. The vehicle came to a complete stop to avoid crashing into traffic, and then sped up when cars started moving again. It was really impressive, and something that sets the 2018 Cadillac CT6 apart from all competitors.

　　I eventually turned off the highway and headed into Washington, D．C. To turn Super Cruise off, I simply hit the button on the steering wheel again. The green light at the top of the wheel turned off, and I took control of the car.

　　The CT6 had no problem bringing me from New York to Washington, D．C., in Super Cruise mode practically all by itself. It makes me hopeful for a future where I'll never need to touch a steering wheel again.

　　语篇导读　本文介绍了凯迪拉克CT6超级巡航模式的自驾体验。

　　4．What is the text mainly about?

　　A．A report comparing different cars' performance.

　　B．A description of an adventurous journey.

　　C．An advertizement of a new type of car.

　　D．An account of a self­driving experience.

　　解析 D　主旨大意题。根据文章内容，尤其是最后一段可知，本文主要描述了一款车的自驾体验，故选D项。

　　5．What does the underlined word "initiating" in Paragraph 2 mean?

　　A．Taking in. B．Turning on.

　　C．Making out. D．Coming off.

　　解析 B　词义猜测题。根据第三段第一句可知，一个绿灯表示超级巡航模式在运行，所以"我"应该是"打开"超级巡航模式。take in吸收；turn on打开；make out理解，辨认；come off脱离，成功，故选B项。

　　6.What did the writer think of the self­driving mode at the beginning of the journey?

A．Doubtful. B．Exciting.