These days, cars are designed using computers. Let’s look at how a new car is created.
First, several designers talk about the new car and any good ideas that they have. Then they sit down at their computers and draw many sketches. The best two or three drawings are chosen and then more detailed(细节的，详情的) drawings of cars are developed on the computer. You can change the size, shape or color of any part on the computer to see how the car would look and then (73 ) you can choose the best design.
Both the inside and the (71) ________of the car have to be designed. Part of the inside of the car is built so that the designers can sit in it. They can feel if there is enough room inside and if they can reach everything. Then some cars are built—there are more than 15 000 parts of a car to test.
(74) When everything is safe, the cars are made in the factory. Again, computers are used to make sure that all the parts are ready as they are needed. （72）The factory usually stays open all through the night so that the car production never stops.
Fill in the missing word:
“Both the inside and the _____________of the car have to be designed.”
The underlined phrase “stays open” means______________________. (Only in English）
“You can choose the best design.” means:
The best design can __________  __________.
Please translate the following sentence into Chinese:
“When everything is safe, the cars are made in the factory.”
__________________________________________________________________________
The main idea of the passage is
____________________________________________________________________.