B．To introduce two water robots.

C．To inform us of sea exploration.

D．To arouse our interest in sea life.

【答案】　B　推理判断题。从文章第二、三段大意可知，本文主要介绍两种水下自我探测器。故选B。

B

(2018·北京D)

Preparing Cities for Robot Cars

The possibility of self－driving robot cars has often seemed like a futurist's dream，years away from materializing in the real world.Well，the future is apparently now.The California Department of Motor Vehicles began giving permits in April for companies to test truly self－driving cars on public roads.The state also cleared the way for companies to sell or rent out self－driving cars，and for companies to operate driverless taxi services.California，it should be noted，isn't leading the way here.Companies have been testing their vehicles in cities across the country.It's hard to predict when driverless cars will be everywhere on our roads.But however long it takes，the technology has the potential to change our transportation systems and our cities，for better or for worse，depending on how the transformation is regulated.

While much of the debate so far has been focused on the safety of driverless cars(and rightfully so)，policymakers also should be talking about how self－driving vehicles can help reduce traffic jams，cut emissions(排放)and offer more convenient，affordable mobility options.The arrival of driverless vehicles is a chance to make sure that those vehicles are environmentally friendly and more shared.

Do we want to copy-or even worsen-the traffic of today with driverless cars？Imagine a future where most adults own individual self－driving vehicles.They tolerate long，slow journeys to and from work on packed highways because they can work，entertain themselves or sleep on the ride，which encourages urban spread.They take their driverless car to an appointment and set the empty vehicle to circle the building to avoid paying for parking.Instead of walking a few blocks to pick up a