write TRUE if the statement is correct and FALSE if it is wrong
1.check the engine oil level on a flat,level surface before using the pump. 2.you can add fuel in the pump even it is running. 3.you can operate tje pump without water for an extended length of time. 4.water pumps are used for testing the concentrations of salt water and brine. 5.before switching on the pH meter,install the batteries. 6.calibration is necessary and should be done regularly. 7.remove battery from instrument that you do not use for a month or more. 8.avoid repeated or prolonged contact with skin or breathing vapour from water pump. 9.never use contaminated gasoline or an oil/gasoline mixture. 10.clean the machine and check the conditionof its part.
