单项选择题
A. improve efficiency B. increase production C. reduce workload D. improve comfort
A. The guest who ate his peas with a knife. B. The other guests who were amused or shocked. C. The host who picked up his knife and began eating in the same way. D. None of the above.
A. Two Important Tests on Airplanes B. The Importance of Flying Safely C. The Danger of Testing Airplanes D. How Airplanes Are Made and Tested