【单选题】I felt very tired when I got home,and I ________ straight to bed. (2013·重庆,21)
【单选题】(2013·高考重庆卷)I felt very tired when I got home,and I________straight to bed.
【简答题】依据固体输送理论怎控制物料与螺杆的摩擦因数 f g ,物料与机筒的摩擦因数 f b ,可以提高固体输送率?实际生产中有哪些方法可以控制摩擦因数?
【单选题】I felt very tired and soon fell . [ ]