somsri starts to work (at, in) nine o'clock sharp in the morning. she works hard all day long. she stops working at four o'clock (at, in) the afternoons. therefore, her work lasts six hours a day
somsri starts to work (at, in) nine o'clock sharp in the morning. she works hard all day long. she stops working at four o'clock (at, in) the afternoons. therefore, her work lasts six hours a day