题目内容：

Three engineers and three accountants (会计) are traveling by train to a conference.At the station，the three accountants each buy tickets and watch as the three engineers buy only a single ticket.

“How are three people going to travel on only one ticket？” asks an accountant.“Watch and you’ll see，” answers an engineer.They all board the train.The accountants take their respective seats but all three engineers cram into a restroom and close the door behind them.

Shortly after the train has departed，the conductor comes around collecting tickets.He knocks on the restroom door and says，“Ticket，please.” The door opens just a crack and a single arm emerges with a ticket in hand.The conductor takes it and moves on.

The accountants see this and agree it is quite a clever idea.So after the conference，the accountants decide to copy the engineers on the return trip and save some money.When they get to the station they buy a single ticket for the return trip.

To their astonishment，the engineers don’t buy a ticket at all.“How are you going to travel without a ticket？”asks one puzzled accountant.“Watch and you’ll see，” answers an engineer.When they board the train the three accountants cram into a restroom and the three engineers cram into another one nearby.The train departs.

Shortly afterward，one of the engineers leaves his restroom and walks over to the restroom where the accountants are hiding.He knocks on the door and says，“Ticket，please.”

1. The three engineers buy only a single ticket because________.

A．only one of them need buy a ticket

B．the three accountants buy tickets for them

C．they just want to save money

D．they are too poor to buy more tickets

2.The underlined word departed in the third paragraph means________.

A．started out  B．separated

C．stopped  D．arrived

3. We can infer from the passage that________.

A．the accountants are not as clever as the engineers

B．the accountants are cleverer than the engineers

C．the engineers are not as clever as the accountants

D．the engineers are as clever as the accountants

4. Which one of the following is TRUE according to this passage?

A．Only one engineer is in the restroom when the conductor collects the ticket.

B．At first the three accountants know why the three engineers buy one ticket.

C．On the return trip the three accountants buy three tickets again.

D．On the return trip the three engineers don’t buy any ticket.