2 . 听下面一段较长对话，回答以下小题。

3 . If you had boarded a passenger plane in 1950, you would have seen five people in the cockpit (驾驶舱): two pilots, a radio operator, a navigator and a flight engineer. Over the years, technical advances have gradually removed the need for the last three, leaving just two pilots. That has been the norm (标准) in commercial aviation for decades.

However, things could be simplified further — one of the two remaining pilots could soon go. Many military aircraft are already manned by a single pilot, and for commercial aviation this would mean stepping into a brave new world.

But how will airlines make this brave innovation come true? One way is to greatly increase automation in the cockpit, devoting more tasks to computers. Another is to shift the same tasks from the cockpit to the ground. “The latter approach seems to be more workable, at least in the short term, because much of what is required already exists,” says Patrick Smith, an airline pilot flying Boeing 767 aircraft. “A trained ground operator could observe a number of flights at once and even fully control the plane remotely if needed.”

It’s true that single-pilot operations could help airlines save money, but there is another reason which makes them quicken their pace for this crucial breakthrough. Boeing predicts a need for 600,000 new pilots in the next two decades, but by some estimates, there will be a deficit (赤字) of at least 34,000 pilots globally by 2025. Reducing the number of pilots on some crews or aircraft could lessen the impact of this.

Perhaps the biggest barrier to a single pilot will be selling the idea to passengers. In 2019, Don Hairis, a professor at Coventry University, conducted a survey on the prospect of flying on an airliner with just one pilot. Just a minority of participants said they’d be willing to take that flight, and the general idea was that removing a pilot increased the possibility of accidents. In the study, Harris concluded that the single-crew airliner would be still probably 20 years away.