【多选题】When views of spur gears are drawn, there are several parameters which should be given, include , and the others.
【判断题】When the spur gears are drawn in sectional views, the section lines should be drawn in gear tooth portions.
【简答题】prehens, prehend 表示—
【单选题】影响消费者购买行为的主要因素有( )个。
【单选题】正常听觉,声音由外耳向内耳传导的主要途径是