A. 5% B. 11% C. 20% D. 30% answer: B Analysis: For every 1000 meters increase in altitude, the air density drops by about 11%.
A.±0.5% B.±1.5% C.±2.5% D.± 5% Answer: B Analysis: The accuracy of flow meters complying with GB/T 13466 standard is ± 1.5%.
A. Low noise B. Efficient and stable C. Portable D. Medical certification answer: B. Efficient and stable
Answer: Perform a series of tests to check the discharge pressure, capacity, and energy efficiency, and compare the results with the manufacturer’s specifications.
A. Large flow and high power are conducive to energy conservation B. Compact structure and good sealing effect C. Smooth operation and reliable operation D. These are all answers: D. all of the above are