单选题：Who Came First, the Chicken or the Egg　　I just mailed the ch

　　Who Came First, the Chicken or the Egg
　　I just mailed the chicken and the egg, each in its own separate packaging, and kept careful track of when each shipment was sent from a post office in Cambridge.
　　Massachusetts, and when it later arrived at its intended destination in New York City.
　　In mailing the chicken, I was careful to adhere to the restrictions described in the American Postal Service's Domestic Mail Manual 57, as updated on April 3, 2003. This, the most recent version of the Manual states that: "Adult chickens must be sent by Express Mail. The containers used must pass the standards in International Safe Transit Association Test Procedure IA; be strong enough to endure normal handling; and ensure enough air for the chickens in transit... The number of birds must not be more than the container's limit."
　　I mailed the chicken in a wooden box got from a colleague who does research with birds.
　　Then, I mailed the egg in standard packaging obtained through an industrial su pplier. It's quite simple.
　　I posted both the chicken and the egg at 9:40 am, on a Monday morning, from the Harvard Square post office, in Cambridge, Massachusetts. The staff there told me that this was the first chicken anyone had mailed from there in recent memory, and perhaps ever. They handled both the chicken and the egg skillfully and politely.
　　The intended destination for both packages was the James A. Farley General Post Office, which is located in Manhattan right next to the Penn Station train terminal. I took the subway from the Harvard Square to the Boston train station, and from there boarded a train to New York City, a distance of about 320 kilometers, arriving that afternoon at Penn Station. I immediately went to the post office, to await the arrivals of the chicken and the egg.The James A. Farley General Post Office is open 24 hours a day, so I was able to wait there until both items arrived. I inquired once per hour for both the chicken and the egg.
　　That day, Monday, neither the chicken nor the egg arrived. The next day, Tuesday, neither the chicken nor the egg arrived.
　　The chicken arrived at 10:31 am, Wednesday. The staff at the post office told me that this was the first chicken anyone had mailed to the post office in recent memory, and perhaps ever. The egg arrived that same day, at 9:37pm, 11 hours after the chicken.
　　Based on experiment data, it's now quite clear that the chicken came first, the egg second.Which of the following is Not required of a container. A．It should be mastic of stee
B．It should be ventilate
C．It should be sufficiently larg
D．It should be stron