题目内容：

With an improved economy, many travelers have been buying first and business class seats, leaving fewer for upgrades (改善) . Here are some strategies for scoring a free upgrade.

1. Fly a lot.

This is the most common way to earn a free upgrade. Most airlines reserve some space for travelers who fly at least 25,000 miles per year. Five years ago, this meant half or more of domestic (国内的) first class travelers sat up front for free. But now, airlines are selling more high price seats, so on popular routes it is not unusual for more than 40 travelers to compete for one or two upgrades. But on routes with fewer business travelers free upgrades remain more plentiful.

2. Use miles.

If you’re not a frequent travelers but still have some miles banked, you may be able to use them for an upgrade. Be careful, though, as many airlines now ask not just for miles but also a cash co-pay. One example: On flights to Europe, American Airlines charges 25,000 miles, plus $350, for a one-way upgrade from discounted economy to business class. For most domestic upgrades, American wants 15,000 miles plus $75.

3. Get lucky.

Sometimes airlines overbook coach, and a few travelers get no seats, only because no seats remain in back. Agents try to ensure the airline’s most loyal travelers get the nod. Sometimes Agents usually have some flexibility to make sure the plane is full and takes off on time. So it’s the easiest way for them to do it —they might upgrade someone else out of order.

4. Save a life.

Flight attendants don’t usually upgrade passengers, even when empty seats remain. Doctors and nurses who answer an emergency call are sometimes an exception. If they comfort a passenger, flight attendants might allow them to sit in business or first class for the rest of the flight.

1.What might be the best topic for the passage?

A. The best ways to get upgraded to first class.

B. How to get on the flight safely and on time.

C. The best ways to get free flight tickets.

D. How to save a life on a plane quickly.

2.Who can have the chance to get a free upgrade?

A. The person who always obeys the rules on the flight.

B. The person who saves the plane immediately and safely.

C. The person who is a friend of the flight attendants’.

D. The person who travels for a long time and long distance by plane.

3.Why might medical personnel be allowed to sit in business or first class sometimes?

A. Because they would like to talk with flight attendants kindly.

B. Because they want to have a complete rest after a long journey.

C. Because they need to treat passengers who are in emergent condition.

D. Because they are tired of staying with common passengers.

4.Where can we find the passage?

A. A life guide.    B. A travel guide.

C. A shopping guide.    D. A pilot guide.