【单选题】_____ about the safety of her son, John's mother looked upset. [ ]
【单选题】The major difference between modern private and public libraries lies in
【判断题】In the statement, "Volvo develops its cars for buyers to whom safety is a major concern, positioning the vehicles as the safest a customer can buy," buyers to whom safety is a major concern is the tar...
【多选题】当一对齿轮的材料,齿数比一定时,影响齿面接触强度的几何尺寸参数主要是( )
【多选题】当一对齿轮的材料,齿数比一定时,影响齿面接触强度的几何尺寸参数主要是( )