【单选题】( ) is a layer of membrane wrapped, containing a variety of acidic hydrolases of vesicular organelles. The main function is digest foreign matter, bacteria, or lost functioning organelles in cells.
【简答题】The source of the pressure for operating the airspeed indicator, the vertical speed indicator, and the altimeter is the pitot-static system. The major components of the pitot-static system are the imp...
【单选题】The mind is but a barren soil; a soil which is soon exhausted and will produce no crop, or only one, unless it be continually fertilized and enriched with foreign matter.