【单选题】A 2-year-old boy came to the doctor due to systemic convulsions with acute upper respiratory tract infection, T39 °C, in order to determine the cause of convulsions, you should focus on which aspects...
【单选题】About a fillister cap screw joint, the nominal diameter of the screw is 10mm and the upper part thickness with straight through hole is 10mm, in addition, the lower part with blind threaded hole is ca...