Questions 11 to 15 are based on the following passage: Today air travel is very common, but the first flights were very different from today. When air travel began in the 1920s, it was very expensive, and most people continued to travel by train or ship. Only the rich and adventurous could afford to fly, and they expected the same kind of luxury they could get on a ship. The first planes had chairs with cushions, and table sets with tablecloths, china, and fresh flowers. The passengers ate wonderful meals, served by men wearing white jackets and gloves. Unfortunately, the trip wasn’t always smooth. The first planes shook and many passengers became sick. Passengers were able to open the windows to get fresh air, but when they landed, mud came in the window. The planes were freezing, so people had to wear warm coats, scarves and gloves. The planes were also extremely noisy, so people couldn’t talk to each other. To communicate, they had to yell or write notes. Back then only men worked as flight attendants. Their job was to carry passengers’ luggage, serve the meals, and keep people safe and warm. They even put cotton in passengers’ ears to block the noise, and gave them brown paper bags when they felt sick. In the 1930s, women began to work on airplanes. The first female flight attendants were all registered nurses. They wore green suits on the ground, but in the air they wore white nurses’ uniforms with caps. During the flight they held the hands of scared passengers, and helped passengers who became sick. After the flight, they had to dust the plane inside and out, and help the pilot put in fuel. Gradually, more women were hired. Only young and attractive women were accepted, and the airlines told them to smile at the passengers all the time. They were not allowed to marry or to have children. Today both men and women work as flight attendants. They wear the same kinds of uniforms, and do the same kind of work. Question: Which is the most probable reason why very few people traveled by air in the 1920s?
A、Because it was too expensive.
B、Because it was too uncomfortable.
C、Because it was too dangerous.
D、Because it was too noisy.
题目内容
（请给出正确答案）
简答题官方参考答案
（由简答题聘请的专业题库老师提供的解答）
