For an ordinary four-stroke engine the inlet valves open ()
A、after TDC
B、before TDC
C、after BDC
D、before BDC
A、after TDC
B、before TDC
C、after BDC
D、before BDC
A、They work four hours and have four hours for rest. B、They work eight hours and have four hours for rest. C、They work four hours and have eight hours for rest. D、They work eight hours and have eight hours for rest.
A、the information can be received on an ordinary FM radio B、warnings are printed out for reading when convenient C、broadcasts are at scheduled times D、a low frequency band is used for long distance transmission
A、loss arising from the subject itself because of its inherent qualities B、loss caused by the ordinary evaporation of liquids C、loss caused by heavy weather D、the natural decay of the vessel due to the passage of time