标准容器是指按照企业标准与技术要求制造的物流容器,这类物流容器不仅适用于一个企业内部,而且适用于整个供应链,乃至跨行业的范围。()
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What's the weather like that night?
A. Clear with few stars in tile sky.
B. Cloudy but with plenty of stars in the sky.
Clear with lots of stars in the sky.
【B17】
A. neighbors
B. army officer
C. mother
D. fellow soldiers
听力原文:M: Did you go to the theater last Saturday?
W: Yes, I saw The Tea House. The acting was excellent.
What did the man do last Saturday?
A. He saw a play.
B. He acted in a play.
C. He went to the tea house.
Before a new type of airplane goes into service, every part of it is tested again and again. But there are two teas that are more important than all the others.
The first is called the "tank test". A modem airplane must fly very high in the sky. Air must be pumped into the plane so that the passengers can breathe. The metal structure (结构)of the plane has to be very strong for this reason. When the plane is filled with air, the air presses against the skin of the plane inside. The pressure (压力) on a small window is like a huge foot that is trying to get out. If a small part of the plane were to fail, the plane would explode in the sky. To test the structure of the plane, the plane is lowered into a huge tank or container of water. Then it is filled with air. The pressure inside the plane is greater than it ever will be when it is high up in the air. Finally, there is an explosion. This does not cause so much damage inside the water tank as it would anywhere else. Engineers can discover which part of the plane has broken. Then that part is made stronger.
The most dangerous test happens when the new plane is going through test flights in the air. The test pilot must find out exactly what happens when tile engines (发动机) are all shut off at once. The plane begins to fall like a stone. It is the pilot's job to find out how he can get control of the plane again. These two tests are examples of how planes are made safe before they ever carry passengers.
By doing the "tank test", the engineers can find out ______.
A. the amount of air in the plane
B. the strength of the plane structure
C. the pressure inside and outside the plane
D. the power of the airplane engines